I just found this. Very good and informative. As an owner of a lyophilizer service company I only have 1 criticism. You keep stating that no heat is applied. This is against the criteria of sublimation. Heat is ALWAYS used in freeze drying. This is how you achieve sublimation and desorbtion in time. Heat is applied either radiantly, or more common, through conductance. Other than that, very informative.
Considering you need a vacuum of at least 611 pascals to reach the triple point of water, where it goes directly from ice to gas at 0C or higher, do you still need to apply external heating to the vacuum chamber? Is the freeze drying apparatus being in a room temperature environment not enough, seeing as theoretically the ice sublimates at 0C and above anyway? I've read that for the tail end of freeze drying things like fruit or other organic material you sometimes need to apply a small amount of external heat to overcome the molecular attraction between that last bit of water and whatever it is locked inside of, but for the first 90-95% external heat should not be necessary I thought?
awesome project! buying a lyophilizer is expensive even used...it's cool to see this done so cheaply (other than the vacuum pump). ill have to give this a try!
@@thethoughtemporium My second question is do you think it would be possible to modify a deep freezer to hold the required vacuum and have a separate water trap compartment built in as well?
@@davidmontoya3997 No, typical deep freezers are not built with vacuum sealing in mind, You would likely end up swapping out the entire interior compartment and the door along with all sealing elements. By the end it would likely just be cheaper and easier to build a vacuum chamber that size from scratch and then to cannibalize the refrigeration system from the deep freezer to cool the vacuum chamber. That is effectively what you would end up with anyway if you tried to convert the deep freezer into a deep vacuum chamber.
I just watched the King of Random do something with freeze drying. I was a bit curious on how the process was done so I googled it and you were the second video. The first being basically and ad for a freeze drying company. This was really neat. I figured it had more to do with a vacuum considering the cost of the pre built machines. Thanks.
You are just like an young version of Ben from Applied Science, someone who I have a lot of respect for. I hope you continue to make such great videos on diverse topics!
Wow. I used to use freeze-dryers (Edwards) for lyophilization of pharmaceuticals from both aqueous & non-aqueous solvents. Our shelf temperatures within the lyophilization chambers were on a separate temperature control circuit so we could drive the process by adding heat to the subliming vials of product. I also used the chambers to add a special gaseous headspace to a liquid diagnostic product that is on the market today. I was actually given a product that I had performed pre-approval development work on. Of course most of the products I worked on were for cancer or HIV, so I am quite glad I never needed those. BUT, I never got to lyophilize STRAWBERRIES!!!
One of the only video I could find. Thank you. Was trying to see if I could build a big one like almost walk in. And how they actually worked. Thanks great video.
That's a lot of -pressure in a huge area, basically a bomb if it fails. Unless you're working for NASA, it's going to cost about a Mil in steel and labor for welding the structure alone.
@@gina248 even the "home" model harvest right is 3000$ and it doesnt even come with the software id need for my applications (hash lol) needs the pharma grade software . the pharma grade HR is 7000$. to rich for my blood. air dry it is haha
This is quite late, but instead of Teflon tape, use a product called nylog on your thread fittings. It acts as both a thread lubricant and a thread sealant. It never dries or cracks. It's what I use on all of my refrigeration systems I need to evacuate. My manifolds can easily reach 50 microns Hg/50 mTorr. I have found that Teflon tends to be a bit leakier. With that said, I also only used tapered fittings or flare fittings on my vacuum setups.
If you ever need to make more cryo insulation I would recommend closed cell polyethylene foam. We use it at work for LN2 plumbing and it works a treat. If you stick with the polystyrene though I would recommend investing in some nichrome wire, a 12V battery, and either a high power pot for voltage splitting or, for more efficiency and less heating, a variable buck converter to adjust the voltage across the wire. Basically I'm describing a DIY hot wire foam cutter. A lot better than using an exacto, I can tell you that much.
I think keeping the drying chamber below freezing during the entire process is preferred. That is to say, below freezing and not below zero F. Sublimation still occurs and you don't have to worry about the cellular structure getting smushy.
they do sell heating mats for them. i doubt freezing is the best.. after all temp differences are used to move gasses, or to make gases liquid or liquid into gases.. (and that is what we are working with in this method) the importent thing is probetly the temp diffence, and not the temp. as long as you stay within where nothing usefull is destroyid in big amounts.. terpens can be collected with freeze drying (with the right temps), so you can also collect the taste and smell to some degree. (and those are not collected when the proces is at its coldest point) probetly not anuff to taste any difference, but you would be able to collect some very tastefull and nice smelling aromas
I've always been interested in making one of these myself, very nice. The only thing I would change is get rid of the styrofoam and get some closed cell foam, like the sheets of insulating foam you can get at the big box hardware stores. Easier to cut clean edges with.
@@chancetolbert4852 I think the temperature needs to swing a bit to entice the sublimation, but I have always wondered if just sealing up my deep freeze and putting a vacuum would work for some foods. I know it's worked on a few steaks I forgot about at the bottom of mine.
Can i use a rolled ice cream machine to sit the big pot on instead of dry ice? Will it be cold enough or maybe that plus dry ice? I would think the rolled ice cream machine could help maintain the temperature? I know this is a old video but can't find a answer to my question anywhere. Thank you to anyone with information
A/C accumulator w fittings A/C oil A/C condenser HD vacuum pump Vacuum pump fitting & sealant Temp gauge Put condenser into container & seal holes, Fill w enough oil to fill condenser, Attach both lines of condenser to accumulator, Attach vacuum fitting, Apply vacuum until reaches preferred temp, Freeze w/e for however long The end
BTW, regular J-B Weld, and long set time epoxies in general, are stronger than the quick set ones. The quick set kinds use different chemicals that result in a weaker resin.
The dry ice purchase itself is ridiculously expensive What did it cost to build this and break down cost to freeze dry strawberries? I freeze dry food now in regular freezer, lay it out on baking sheets, flip every couple days, in 10 days or so, depending on what im freezing, up to 3 weeks. Stand up freezers are great for this and a lot cheaper
Crushing the dry ice to a powder speeds up the process and Ive used paint thinner for a cryo liquid but I was just messing with stuff cause I get free dry ice sometimes
Dollar Tree Stores have small bags of freeze dried fruit for $1.00. Strawberries, peaches, apples, mixed fruit. 70-80 calories a bag. An alternative for those of us that like freeze dried foods as snacks but don't have time or money for freeze dryer.
En Person The comment should read 'has' in the places it now reads 'have' as 'Astronaut Cream' is singular. Now if you said Astronaut Creams, flavors, types, or varieties, 'have' would be appropriate
En Person You're only half right. It never went to space. But it was developed under a NASA contract for the Apollo missions. So it was very much intended for them to eat it. The problem was it was found to be to crumbly, so it didn't get to go.
That’s amazing. Could you please estimate how much time and cost would it take to prepare specified amount (100 grams for example) of fruit like strawberries and other food that you tried it with?
A yield of 20-30% would be good. He says 6-14 hours after flash freezing. I run industrial multi phase freeze dryers with 1500lb capacity and takes us 17-19 hours depending on size and type of product
Oh lordy.. I was looking at freeze dryers and there's no way I can afford 2 or 3 thousand dollars for one. Then I think ... Hey, maybe I could build one.. Then I see this and look at my DEHYDRATOR and tell it, Don't worry, I'm not dumping you. Holy crap on a cracker!! LOL Macgyver is staring at me with a knowing smirk like he's saying I told you so lol
The comment at the end about making a carbon foam from bread in the kiln, reminds me of a video I saw from AVE. He did just that by burning the bread without allowing it oxygen. I thought it was really neat, so I've been thinking about it for a while. What if you used popcorn instead of bread? And then, I wondered if you could make high temperature refractory bricks using the presumably resulting carbon foam pellets, by misting it lightly with water, and dusting it with dry (unfired) clay, and repeating this until the pellets build up a thin protective shell of clay. Then you would pack them into a brick mold in layers, with a light mist of water and a light dusting of clay in-between each layer. I think a handheld old fashioned flour sifter would help to apply the dust evenly. I also wonder of being able to incorporate grog (crushed, fired pottery), in dust or fine grit form, to help with thermal shock, incase the version made without it has any trouble. Anyway, the brick should be allowed to dry very thoroughly, and not too quickly, so that it doesn't explode in the kiln, or crack while it's drying, from the pressure of water vapor trying to escape too quickly, or the strain of the brick contracting unevenly from drying out. I also thought about adding the clay shelled carbon foam pellets to the kiln individually, but I wonder how you'd get them packed in efficiently, without having them all stick together during the firing, if they're touching eachother. Maybe coating them with some kind of ash? But if you could fire them as individual, loose pieces, you could probably actually use them as grog for clay bricks, without actually crushing them up, like one would normally do. That way, you could create custom shaped refractory clay pieces for ovens and things, without having to try to make them from assembling a bunch of bricks.
@@fistpunder They don't bother with lists any more, they just watch everybody and store all communications. Or were you not listening when Snowden spoke up?
Ebay links are prone to link rot... any chance you could just list the full names of things like the vacuum chambers, cooking pot, vacuum gauge and vacuum pump?
For the sake of food preservation does this need to be super cold? If you don't care that your food keeps its shape would just pulling a strong vacuum dry it out? Or will this cause it to be unappetizing? This would be much easier and cheaper that cooling it down.
Looking at the phase diagram, I have a question about temperature, why do we need to deeply the items that much? Wouldn’t regular household freezer temps be ok with -5 C° for example? As the line between 10 mBar and 1 mBar is crossed, water will sublimate. No? Second question is about the pump. Isn’t there a pump able to release water into the air without rusting? Of course the gas will turn to liquid water as soon as it leaves the pump and hit 1 Bar.
Could this work just freezing the food, and then putting it in a vacuum generated by a hand-pump? I'm trying to make a science-project on how to freeze drye food with only a few tools and materials.
Wouldn't a Sprengel vacuum pump work? A simple pump is much cheaper to buy and run. Nerd rage built one for $50 and achieved with water and a 100psi pump almost the pressure you want. Changing to mineral oil or vacuum oil to improve performance further would mean you can boil off the water at sub 25C without the need to freeze the fruit. The water that comes off can be separated through a simple oil water trap made with a sheet of plastic. So you can cycle the same fluid around, and it doesn't require cooling. This would be lower investment cost and lower running cost. However I've not built or tested this, so I'd appreciate any information as to why this wouldn't work.
Do you mean a water aspirator pump? A Sprengel pump is what Cody's Lab made, it uses mercury falling through a small capillary tube to evacuate the air. It pumps far too slowly to do the job. However, as far as I can tell an aspirator pump will work. I found this paper images.peabody.yale.edu/lepsoc/jls/1970s/1976/1976-30(4)277-Hedges.pdf talking about doing exactly what you describe. The drying process was very slow using water as the working fluid but as you say, could be improved by using mineral or vacuum oil.
For the vapor trap, I used some stainless steel fins from some scrap 304 stainless steel to increase the surface area and help less water vapor make its way into the Vacuum pump. I learned that the hard way and ruined a $1000 vacuum pump and vacuum fittings.
How exactly do I understand what compressors output enough militorps. Trying to google an understanding of what militorps are came up half empty and I’m still not understanding what it’s relevance to psi is? If anyone could explain I would appreciate it.
Great video but in the long run... the initial low cost of a DIY unit will end up costing more than a retail unit, due to the unavoidable need to replenish the dry-ice, given dry ice is a consumable and can be pretty pricey in cetain markets :( The most cost-effective solution, of course, would be to find a used retail unit for cheap or (better yet) split the cost with someone/a group of ppl, to help lower the rather steep initial cost. On a side note/for what it's worth... many people forget that DIY & retail freeze dryers typically need to operate for many (many) hours, so depending on the water content of the particular food being freeze-dried, the freeze dryer may need to run for 12 hours, or more, which (unless one lives where electricity is cheap or they have a solar system) there's going to be a noticeable increase in one's electric bill when running a freeze dryer...the point being...it might be a lot less expensive to simply spend/invest the $3000-$5000 (plus food costs) on food that has already been freeze dried by a commercial company(?)
A pump like that is around 300-400 watts. A "home unit" by greenworks is 750 watts. So it costs less in that aspect. Secondly you don't need an astronomical amount of dry ice. Only about 6 dollars worth
Quick question: maybe I missed some clue but why you using dray ice - do you really need so low temperature? I would expect that frizzing samples and keeping below 0 centigrade would be enough and also most energy efficient as I would expect the higher ratio of sublimation just below 0 then in -40
Actually the sublimation line exists below the triple point so you just need to keep the food cooler than 0.16C. However you do need a margin so that no part of the food reaches the triple point. Indeed, at higher temperatures less of a vacuum would be needed. However texture and quality can be improved by what's called IQF which stands for Individual Quick Freezing. Dry ice would be good for IQF. I think this DIY'er made it harder on himself by insisting on such a low temperature and extreme vacuum. The phase charts for water suggests that such extremes are not needed and indeed historically the ancient Incans freeze dried foods by climbing mountains and leaving the foods exposed at the summits. Commercial freeze dryers actually heat the product after the vacuum has been applied.
Also freeze drying food stops histamine growth completely making it the ideal food storage method for those suffering from gastrointestinal discomfort.
Hi Thought Emporium, im gonna build a freeze dryer and i watcherd your video but i have a question: when the water sublimates off the food, does it travel thru the tube to the cold trap to condense as solid there or is that a secondary condenser with the primary collection of water happening inside the food holding vaccum chamber? im not sure if i need to keep a cold finger in the vaccum chamber with the food or not.
I saw this video on your blog page, and I thought it was funny how someone was like "Meh! You must not use super glue on polystyrene!!!" when you in fact did not use super glue on polystyrene. lol. Anyway, great video, thanks for it. It helped me out a lot with my own built.
Yikes, your micron gauge isn't made to be tightened with a pipe wrench and will likely rip the oring. Protip use some vacuum pump oil on the oring and hand tighten.
Eric Dalgetty Having a dry o-ring shred or just being dry would also cause leaks too so a little does go a long way. But you are right too so there's a balance...
I was wondering why not just use liquid nitrogen for your cryofluid? Did you just not want to buy a fancy dewer, or is there some other reason why liquid nitrogen isn't being used here?
Hey, love your video :) i want to build machine like this on my own and i have a 2 questions: 1. how do you prevent water from going directly to the pump from the water trap? 2. how do you know when the process is finish? and you products is completely dried? and when i turn off the pump? Thank you :)
I know this is 5 years later, but if I need to do vacuum steam distillation, can I use the same setup, but an induction burner to do 135 or so to boil off the water?
Why is the water trap necessary? Wouldn't the pump remove the water vapor anyway? I mean depending on your pump its probably a bad idea but that would depend on the pump...
one small point, don't use regular spray adhesive on polystyrene, the propellant and the solvent in in dissolves the polystyrene, same is true for a lot of plastics, you need the one that's specifically made for plastics though to pay through the nose for it
tigoda85, 3m brand super77 contains acetone, and that eats most foams. Yet if you take said adhesive and spray thin, light coat from a distance of 16 inches approximately on both surfaces to be bonded, it won't melt foam. Acetone evaporates before it reaches the surface. You'll tear the foam apart well before you tear the glue seam. Great adhesive for using a hotwire cutter on laminated foam
Do you need to keep the pump running once it has created the vacuum? Could you get away with putting the food into the vacuum chamber, bringing it to full vacuum and then sitting the chamber inside a freezer for a few hours until the food freezes and the water sublimates from it? The sublimation would create some pressure inside the chamber but if you kept the batches small it would just condense on the sides of the chamber as frost. As a note, I'm thinking about this from a food storage standpoint.
Ya you can't turn the pump off till it's done. It loses pressure very quickly the second you turn it off from the massive amount of water vapour coming off the items
Had to rewatch this video again for cold trap inspiration... Do you think this design would work for capturing methanol/VOC's in a vacuum percolation device? I'll be bubbling humid air through distilled spirits to expedite oxidation reactions and simulate gas exchange in a barrel. I have access to a diaphragm pump (not PTFE.... But I want one someday...) that can go down to 27in Hg, and I don't want too many vapors to condense in the pump itself... Is there a cold trap design you'd recommend for the budget-conscious creator?
I understand how you built everything but i have no idea if the drying chamber and water trap are tied together??? I really want to copy your set up but im a little lost on the whole water trap.. If anyone could explain to me what I'm missing I would greatly appreciate it!! Does the drying chamber just sit in the water trap?
A question for the PhDs: I've watched snow sublimate in sunlight with temperature in teens, with concrete actually dry. Sometimes even 'steam' can appear. Snow in thin layer. Layers of snow actually also reduce without obvious melting (liquid). So can a freeze dryer be made say cooling down to 10F, with a sun lamp, in a very dry or vacuum environment?
Yes, that was my query too. Looking at the phase diagram for water, he actually made it harder to freeze dry by cooling to such an extreme and having such an extreme vacuum. The sublimation line stretches from zero pressure and absolute zero temperature to the triple point of water so really all that should be needed is keeping the temperature below the triple point (0.16C) by enough of a margin so there is no danger of liquid water forming and then having a partial vacuum, the higher the temperature, the less of a vacuum would be needed to sublimate the ice. I think he shot himself in the foot with this experiment. Now rapid cooling of the product could help preserve the quality and texture so initial quick cooling with dry ice may be useful. If I was to home dry freeze, I would quick freeze the product with dry ice then place it into mason jars, use a foodsaver jar attachment to create a partial vacuum. The foodsaver's pump can remove just less than half an atmosphere which should be enough if the temperature is high enough but you can use an automotive or AC vacuum pump including the hand brake vacuum pumps to remove 90% of atmospheric plus those pumps are intended for removing water vapour so a cold trap would not be needed to protect the pump. The automotive brake and AC pumps happen to use the same hose size as the foodsaver jar attachment. Then it's a matter of keeping the jars in the deep freeze with periodic vacuum draws for days. Weighing the jars would show you how much water has been removed and the USDA publishes a list of the water content of common foods. I suspect it would take days to weeks to freeze dry foods this way.
@@trevorfichtner3539 Well, it isn't just the vacuum that matters we just have the most data on temperature and pressure with phase diagrams, but it's the vapour pressure so to preserve the terpenes, I would suspect using zeolites to preferentially reduce the water vapour pressure as the air pressure is removed. Ideally a membrane could be used so that the vacuum drew out more water vapour than terpene pressure, you would still lose some, the hope is to remove less of what you want preserved. The water trap is cold obviously to condense as much of the water vapour as possible, it's like how a dehumidifier works, the evaporator is simply colder than what's being dehumidified. Obviously condensation isn't the only way to remove water vapour, you could absorb them instead again with zeolites, some silica gel packets can do a lot to help with your DIY home freeze drying (note again, though zeolites for selective absorption, they do absorb some of what you don't want absorbed, nothing is perfect). Short of finding the phase diagram for terpenes to see if there are any differences from the phase diagram of water you could take advantage of, the best course for home experimentation would of course be to just try a few variations and work out a systemic way of deciding which worked better. Terpene is presumably a complex organic compound so it may have a rather complicated phase diagram with some of it's components behaving differently than others so you also have the possibility of possible decomposition. Maybe you should try contacting commercial marijuana producers to see what they do, it's always best to survey what's already being done first.
Yeah snow can sublimate partly because winter brings low humidity and the crystals can be especially effected by sunlight. I don’t think the conditions of a freeze dryer would be as applicable, maybe it could help a bit tho. Worth a shot but you’d probably want the lamp inside the chamber and that’s a pain
@The Thought Emporium I cannot stress how grateful I am for your work, My 13 year old is just finishing putting the thing together for me, obviously I will be connecting the VAC pump and operating the machine, thanks again. Have you ever thought of building an electron microscope (its been done before)
When I was searching for DIY Freeze drying, I was really hoping I'd find a video that said -- "Stick desired freeze dried item in the very back of the freezer and wait"
Go to Cody's lab and check the one he made powered by mercury, that should do the trick, it's really cheap as it has no moving parts and you get a free workout
Is the cold trap really necessary? It seems to me that it would only be needed to protect the pump from corrosive chemicals that would not be compatible with it's internals. I can understand that water vapor would physically mangle a turbo-molecular pump, but I would think a vain or diaphragm pump would be more robust. Is it just a case of it not being practical to make a pump that gets you to that level of vacuum and can handle some water vapor?
Over 20ml of water was in the cold trap when I let it thaw out, so ya it's super neccasary. The issue isn't the pump per say, that you're screwing with the oil in the pump which can then mess with the pump. Or if condensation is left inside the pump when it's turned off it'll rust internally
RRRRIIIGGGHHHHTTTTT. LOL I simply bought a Harvest Right home freeze dryer back in Dec 2081 - I run it almost 24/7 and have processed a lot of foods for long term storage. Compared to buying commercially produced FD foods - my dryer has paid for itself many times over. It will also process up to 20 pounds of foods in a single batch. Good luck with your DYI dryer.
Can anyone help me out with this? Do you put anything inside the cold trap or does it stays empty? Is that where you freeze the food or does the food has to be frozen first?
![Felix "Unfair" | [Stray Kids : SKZ-PLAYER]](http://i.ytimg.com/vi/Oswujxm2Ag0/mqdefault.jpg)
top 10 ways to make your neighbors think you have a meth lab
I need them to know where to get it
Hah…so true. Can’t imagine the in-laws or a landlord seeing this set-up sprawled across the kitchen, with no explanation.
😂
Shhhhhhhhhhhhh it is weed stuff I swear mam I just separated the resin from the plant
jesse we need to freeze dry fruits
I just found this. Very good and informative. As an owner of a lyophilizer service company I only have 1 criticism. You keep stating that no heat is applied. This is against the criteria of sublimation. Heat is ALWAYS used in freeze drying. This is how you achieve sublimation and desorbtion in time. Heat is applied either radiantly, or more common, through conductance. Other than that, very informative.
Considering you need a vacuum of at least 611 pascals to reach the triple point of water, where it goes directly from ice to gas at 0C or higher, do you still need to apply external heating to the vacuum chamber? Is the freeze drying apparatus being in a room temperature environment not enough, seeing as theoretically the ice sublimates at 0C and above anyway? I've read that for the tail end of freeze drying things like fruit or other organic material you sometimes need to apply a small amount of external heat to overcome the molecular attraction between that last bit of water and whatever it is locked inside of, but for the first 90-95% external heat should not be necessary I thought?
awesome project! buying a lyophilizer is expensive even used...it's cool to see this done so cheaply (other than the vacuum pump). ill have to give this a try!
Thanks :) Ya I was looking at buying a used one, but the price was insane. Was so much easier to just build it.
@@thethoughtemporium how well would it work to use a used refrigerator compressor for the vacuume pump?
@@davidmontoya3997 not at all. needs a better pump than that.
@@thethoughtemporium My second question is do you think it would be possible to modify a deep freezer to hold the required vacuum and have a separate water trap compartment built in as well?
@@davidmontoya3997 No, typical deep freezers are not built with vacuum sealing in mind, You would likely end up swapping out the entire interior compartment and the door along with all sealing elements. By the end it would likely just be cheaper and easier to build a vacuum chamber that size from scratch and then to cannibalize the refrigeration system from the deep freezer to cool the vacuum chamber. That is effectively what you would end up with anyway if you tried to convert the deep freezer into a deep vacuum chamber.
I just watched the King of Random do something with freeze drying. I was a bit curious on how the process was done so I googled it and you were the second video. The first being basically and ad for a freeze drying company. This was really neat. I figured it had more to do with a vacuum considering the cost of the pre built machines. Thanks.
You are just like an young version of Ben from Applied Science, someone who I have a lot of respect for. I hope you continue to make such great videos on diverse topics!
Thanks! Glad you enjoy
Wow. I used to use freeze-dryers (Edwards) for lyophilization of pharmaceuticals from both aqueous & non-aqueous solvents. Our shelf temperatures within the lyophilization chambers were on a separate temperature control circuit so we could drive the process by adding heat to the subliming vials of product. I also used the chambers to add a special gaseous headspace to a liquid diagnostic product that is on the market today. I was actually given a product that I had performed pre-approval development work on. Of course most of the products I worked on were for cancer or HIV, so I am quite glad I never needed those.
BUT, I never got to lyophilize STRAWBERRIES!!!
One of the only video I could find. Thank you. Was trying to see if I could build a big one like almost walk in. And how they actually worked. Thanks great video.
That's a lot of -pressure in a huge area, basically a bomb if it fails. Unless you're working for NASA, it's going to cost about a Mil in steel and labor for welding the structure alone.
awesome build. wish there was a affordable home/mini sized freeze dryer on the market..
Agreed ! I’ve been searching for years for a mini kitchen one and they are all large and expensive
@@gina248 even the "home" model harvest right is 3000$ and it doesnt even come with the software id need for my applications (hash lol) needs the pharma grade software . the pharma grade HR is 7000$. to rich for my blood. air dry it is haha
This is quite late, but instead of Teflon tape, use a product called nylog on your thread fittings. It acts as both a thread lubricant and a thread sealant. It never dries or cracks. It's what I use on all of my refrigeration systems I need to evacuate. My manifolds can easily reach 50 microns Hg/50 mTorr. I have found that Teflon tends to be a bit leakier. With that said, I also only used tapered fittings or flare fittings on my vacuum setups.
If you ever need to make more cryo insulation I would recommend closed cell polyethylene foam. We use it at work for LN2 plumbing and it works a treat. If you stick with the polystyrene though I would recommend investing in some nichrome wire, a 12V battery, and either a high power pot for voltage splitting or, for more efficiency and less heating, a variable buck converter to adjust the voltage across the wire. Basically I'm describing a DIY hot wire foam cutter. A lot better than using an exacto, I can tell you that much.
I think keeping the drying chamber below freezing during the entire process is preferred. That is to say, below freezing and not below zero F. Sublimation still occurs and you don't have to worry about the cellular structure getting smushy.
they do sell heating mats for them.
i doubt freezing is the best..
after all temp differences are used to move gasses, or to make gases liquid or liquid into gases.. (and that is what we are working with in this method)
the importent thing is probetly the temp diffence, and not the temp.
as long as you stay within where nothing usefull is destroyid in big amounts..
terpens can be collected with freeze drying (with the right temps), so you can also collect the taste and smell to some degree. (and those are not collected when the proces is at its coldest point)
probetly not anuff to taste any difference, but you would be able to collect some very tastefull and nice smelling aromas
I've always been interested in making one of these myself, very nice. The only thing I would change is get rid of the styrofoam and get some closed cell foam, like the sheets of insulating foam you can get at the big box hardware stores. Easier to cut clean edges with.
I was considering it but the styrofoam was half the price and fit in the car haha
Couldn't you just tube it up into a deep freezer?
@@chancetolbert4852 I think the temperature needs to swing a bit to entice the sublimation, but I have always wondered if just sealing up my deep freeze and putting a vacuum
would work for some foods. I know it's worked on a few steaks I forgot about at the bottom of mine.
Can i use a rolled ice cream machine to sit the big pot on instead of dry ice? Will it be cold enough or maybe that plus dry ice? I would think the rolled ice cream machine could help maintain the temperature? I know this is a old video but can't find a answer to my question anywhere. Thank you to anyone with information
A/C accumulator w fittings
A/C oil
A/C condenser
HD vacuum pump
Vacuum pump fitting & sealant
Temp gauge
Put condenser into container & seal holes,
Fill w enough oil to fill condenser,
Attach both lines of condenser to accumulator,
Attach vacuum fitting,
Apply vacuum until reaches preferred temp,
Freeze w/e for however long
The end
BTW, regular J-B Weld, and long set time epoxies in general, are stronger than the quick set ones. The quick set kinds use different chemicals that result in a weaker resin.
He said that
I'm gonna use this to make magic mushrooms last super long without being leathery.
That's a good idea
Did it work well?
Do you regularly read minds from afar?
ima have ta hop on this wave
That is just godlike!
The dry ice purchase itself is ridiculously expensive
What did it cost to build this and break down cost to freeze dry strawberries?
I freeze dry food now in regular freezer, lay it out on baking sheets, flip every couple days, in 10 days or so, depending on what im freezing, up to 3 weeks.
Stand up freezers are great for this and a lot cheaper
Crushing the dry ice to a powder speeds up the process and Ive used paint thinner for a cryo liquid but I was just messing with stuff cause I get free dry ice sometimes
Why didnt you just use spray foam to insulate the larger pot?
He didn't have it at the time
Because he wanted to add dry ice underneath
Dollar Tree Stores have small bags of freeze dried fruit for $1.00. Strawberries, peaches, apples, mixed fruit. 70-80 calories a bag. An alternative for those of us that like freeze dried foods as snacks but don't have time or money for freeze dryer.
Dude your videos are really cool and interesting, and im glad that I found your channel. Keep it up.
Fun fact:
"Astronaut icecream" have never been in space and have never been intended to be eaten by astronauts.
If I ever become an astronaut, I know what I'm bringing with me then
En Person The comment should read 'has' in the places it now reads 'have' as 'Astronaut Cream' is singular. Now if you said Astronaut Creams, flavors, types, or varieties, 'have' would be appropriate
Astronaut bacon is a thing
And it needs be known
En Person
You're only half right.
It never went to space.
But it was developed under a NASA contract for the Apollo missions. So it was very much intended for them to eat it. The problem was it was found to be to crumbly, so it didn't get to go.
En Person “has”, not “have”
I’m curious to know what your final build cost was? Freeze dryers are ridiculously expensive.
Right?
Yeah how much
$180 Field Piece SVG3
$30 2 Gallon Stainless Steel Cooking Pot
$100 Two 2 Quart Stainless Steel Vaccum Chamber ($50 each)
$3 1/4” Flare Union
$7 5/8” Barb Splicer
$25 Styrofoam sheets
$15 Spray Adhesive for Foam
$15 High Grade Teflon Tape
$9 J-B Weld
$10 Thermal Work Gloves
$25 Denatured Ethanol
$150 2 stage rotary vane vacuum pump
Total $569
Each time:
$5 Dry Ice
Built on Amazon like 400
@@phylliida You're deeply underappreciated.
That’s amazing. Could you please estimate how much time and cost would it take to prepare specified amount (100 grams for example) of fruit like strawberries and other food that you tried it with?
A yield of 20-30% would be good. He says 6-14 hours after flash freezing. I run industrial multi phase freeze dryers with 1500lb capacity and takes us 17-19 hours depending on size and type of product
@@Scrotux we’re trying to make one
Oh lordy.. I was looking at freeze dryers and there's no way I can afford 2 or 3 thousand dollars for one. Then I think ... Hey, maybe I could build one.. Then I see this and look at my DEHYDRATOR and tell it, Don't worry, I'm not dumping you.
Holy crap on a cracker!!
LOL
Macgyver is staring at me with a knowing smirk like he's saying I told you so lol
can an aluminum pressure cooker be used instead of the stainless steel chambers?
i am really interested in hearing how your carbon foam turns out this was very helpful, Thank you good Sir!
0:01 that building is so good it looks animated
Can you build another one now to see how much h it would cost but that freezes without dry ice ?
The comment at the end about making a carbon foam from bread in the kiln, reminds me of a video I saw from AVE. He did just that by burning the bread without allowing it oxygen. I thought it was really neat, so I've been thinking about it for a while. What if you used popcorn instead of bread? And then, I wondered if you could make high temperature refractory bricks using the presumably resulting carbon foam pellets, by misting it lightly with water, and dusting it with dry (unfired) clay, and repeating this until the pellets build up a thin protective shell of clay. Then you would pack them into a brick mold in layers, with a light mist of water and a light dusting of clay in-between each layer. I think a handheld old fashioned flour sifter would help to apply the dust evenly. I also wonder of being able to incorporate grog (crushed, fired pottery), in dust or fine grit form, to help with thermal shock, incase the version made without it has any trouble. Anyway, the brick should be allowed to dry very thoroughly, and not too quickly, so that it doesn't explode in the kiln, or crack while it's drying, from the pressure of water vapor trying to escape too quickly, or the strain of the brick contracting unevenly from drying out.
I also thought about adding the clay shelled carbon foam pellets to the kiln individually, but I wonder how you'd get them packed in efficiently, without having them all stick together during the firing, if they're touching eachother. Maybe coating them with some kind of ash? But if you could fire them as individual, loose pieces, you could probably actually use them as grog for clay bricks, without actually crushing them up, like one would normally do. That way, you could create custom shaped refractory clay pieces for ovens and things, without having to try to make them from assembling a bunch of bricks.
World Theory wow
Could you freeze dry something bigger, like say a body? Just asking for a friend.
And someone just made a watch list.
LOL
That’s funny!!!
@@fistpunder They don't bother with lists any more, they just watch everybody and store all communications. Or were you not listening when Snowden spoke up?
🤦🏻♂️ lmao 😂😂😂😂
@@mikaelgaiason688 My dude, he couldn't detect the sarcasm in OP's comment, there's no way he was paying attention to Snowden.
How much dry ice (and alcohol?) per hour is used would be interesting to know
Thanks for the video. Now im definatly just going to buy already made freeze dried food even though its very expensive, which i can see why
Can I put damp rid in water collector so it doesnt have to be kept so cold
So, the vacuum pump keeps running the whole six hours? Or you just shut the handle of the water chamber and then turn the vacuum off?
So many of your videos are in my projects playlist. Thanx for your awesome videos as always.
do you have a list of items you used to make this?
Total cost of components used and bought to sum up how expensive this would be?
I would like to get a parts list from you and diagram on how to build this
Thank you for your teaching. May I ask how much costed the material? N how many hrs do you need to make it? Thank you again.
Ebay links are prone to link rot... any chance you could just list the full names of things like the vacuum chambers, cooking pot, vacuum gauge and vacuum pump?
For the sake of food preservation does this need to be super cold? If you don't care that your food keeps its shape would just pulling a strong vacuum dry it out? Or will this cause it to be unappetizing? This would be much easier and cheaper that cooling it down.
Is there a way potentially you could tube it up through a deep freezer and instead of dry ice and styrofoam it just goes inside a deep freezer
can you use an oilless pump so you don't need to condensate the water vapor?
Looking at the phase diagram, I have a question about temperature, why do we need to deeply the items that much? Wouldn’t regular household freezer temps be ok with -5 C° for example? As the line between 10 mBar and 1 mBar is crossed, water will sublimate. No?
Second question is about the pump. Isn’t there a pump able to release water into the air without rusting? Of course the gas will turn to liquid water as soon as it leaves the pump and hit 1 Bar.
Could this work just freezing the food, and then putting it in a vacuum generated by a hand-pump? I'm trying to make a science-project on how to freeze drye food with only a few tools and materials.
You’re so smart
Great project. It worked. The next step is to build a box with massive insulation around the freezers.
Have fun with your *freezing powwrs !*
Overall, how much did this all cost you? And how much would every run cost everytime you need to replenish the dry ice and alcohol?
Wouldn't a Sprengel vacuum pump work?
A simple pump is much cheaper to buy and run. Nerd rage built one for $50 and achieved with water and a 100psi pump almost the pressure you want.
Changing to mineral oil or vacuum oil to improve performance further would mean you can boil off the water at sub 25C without the need to freeze the fruit. The water that comes off can be separated through a simple oil water trap made with a sheet of plastic. So you can cycle the same fluid around, and it doesn't require cooling. This would be lower investment cost and lower running cost.
However I've not built or tested this, so I'd appreciate any information as to why this wouldn't work.
Do you mean a water aspirator pump? A Sprengel pump is what Cody's Lab made, it uses mercury falling through a small capillary tube to evacuate the air. It pumps far too slowly to do the job. However, as far as I can tell an aspirator pump will work. I found this paper images.peabody.yale.edu/lepsoc/jls/1970s/1976/1976-30(4)277-Hedges.pdf talking about doing exactly what you describe. The drying process was very slow using water as the working fluid but as you say, could be improved by using mineral or vacuum oil.
For the vapor trap, I used some stainless steel fins from some scrap 304 stainless steel to increase the surface area and help less water vapor make its way into the Vacuum pump. I learned that the hard way and ruined a $1000 vacuum pump and vacuum fittings.
love the video. is there something you can use in place of dry ice?
What kind of savage slices strawberries with the stem on?
Every single time I want to learn how to diy something super cool, you have a video! Haha thank you!
How exactly do I understand what compressors output enough militorps. Trying to google an understanding of what militorps are came up half empty and I’m still not understanding what it’s relevance to psi is?
If anyone could explain I would appreciate it.
Can you use antifreeze instead of denatured alcohol?
How does the water trap work? The whole idea of a freeze dryer is to get the ice to vaporize, how does it recondence while still under vacume?
Great video but in the long run... the initial low cost of a DIY unit will end up costing more than a retail unit, due to the unavoidable need to replenish the dry-ice, given dry ice is a consumable and can be pretty pricey in cetain markets :( The most cost-effective solution, of course, would be to find a used retail unit for cheap or (better yet) split the cost with someone/a group of ppl, to help lower the rather steep initial cost. On a side note/for what it's worth... many people forget that DIY & retail freeze dryers typically need to operate for many (many) hours, so depending on the water content of the particular food being freeze-dried, the freeze dryer may need to run for 12 hours, or more, which (unless one lives where electricity is cheap or they have a solar system) there's going to be a noticeable increase in one's electric bill when running a freeze dryer...the point being...it might be a lot less expensive to simply spend/invest the $3000-$5000 (plus food costs) on food that has already been freeze dried by a commercial company(?)
Dry ice is so cheap I think this would be great for home growers that only harvest a couple times a year
A pump like that is around 300-400 watts. A "home unit" by greenworks is 750 watts. So it costs less in that aspect. Secondly you don't need an astronomical amount of dry ice. Only about 6 dollars worth
Quick question: maybe I missed some clue but why you using dray ice - do you really need so low temperature? I would expect that frizzing samples and keeping below 0 centigrade would be enough and also most energy efficient as I would expect the higher ratio of sublimation just below 0 then in -40
Unfortunately not. For Lyophilisation, you need very low temperatures so your products don't collapse or even melt. It's a science by itself.
Actually the sublimation line exists below the triple point so you just need to keep the food cooler than 0.16C. However you do need a margin so that no part of the food reaches the triple point. Indeed, at higher temperatures less of a vacuum would be needed. However texture and quality can be improved by what's called IQF which stands for Individual Quick Freezing. Dry ice would be good for IQF. I think this DIY'er made it harder on himself by insisting on such a low temperature and extreme vacuum. The phase charts for water suggests that such extremes are not needed and indeed historically the ancient Incans freeze dried foods by climbing mountains and leaving the foods exposed at the summits.
Commercial freeze dryers actually heat the product after the vacuum has been applied.
Also freeze drying food stops histamine growth completely making it the ideal food storage method for those suffering from gastrointestinal discomfort.
Hi Thought Emporium, im gonna build a freeze dryer and i watcherd your video but i have a question: when the water sublimates off the food, does it travel thru the tube to the cold trap to condense as solid there or is that a secondary condenser with the primary collection of water happening inside the food holding vaccum chamber?
im not sure if i need to keep a cold finger in the vaccum chamber with the food or not.
Wondering if a molecular sieve would work just as well as a cold trap. 🤔🤔🤔
I saw this video on your blog page, and I thought it was funny how someone was like "Meh! You must not use super glue on polystyrene!!!" when you in fact did not use super glue on polystyrene. lol. Anyway, great video, thanks for it. It helped me out a lot with my own built.
How did you do it without slow heating? You saw in the previous videos that the shelves are slowly heated to practice sublimation.
Yikes, your micron gauge isn't made to be tightened with a pipe wrench and will likely rip the oring. Protip use some vacuum pump oil on the oring and hand tighten.
True, but also it was leaking. I was pretty gentle with the pipe wrench, though I realize I should've mentioned that.
Typically I would avoid adding any extra oil inside the chamber, it can offgas and keep the chamber from reaching a good vacuum
Eric Dalgetty Having a dry o-ring shred or just being dry would also cause leaks too so a little does go a long way. But you are right too so there's a balance...
Sterile petroleum jelly works better than pump oil.
There's a product called petrol-gel intended for laboratory use.
huh... its much easier than i thought it would be, this was helpful.
happy to help :)
I was wondering why not just use liquid nitrogen for your cryofluid? Did you just not want to buy a fancy dewer, or is there some other reason why liquid nitrogen isn't being used here?
How much did it cost and how many hours did it take to make this?
Wait I'm confused only the cold trap has to be cold? not the drying chamber or does the cold trap make the drying chamber cold?
I'm wondering if this to be made out of scrap parts like using freezer compressors maybe several of them to make this on a bigger scale
02:25 The diagram says what you need less than 100 pascals at 250K, so why you said what we need ~13 pascals (100torr)
Could frame out around your pot and then use spray foam (just an idea from the hive mind)
youve just got a new sub and you are the 2nd channel where id ring the bell i really like your content
Hey, love your video :) i want to build machine like this on my own and i have a 2 questions:
1. how do you prevent water from going directly to the pump from the water trap?
2. how do you know when the process is finish? and you products is completely dried? and when i turn off the pump?
Thank you :)
Does anyone have a vacuum to recommend that works well? Preferably budget?
Were did you guys find the vacume pump can I please get a link
What would change if I want to build a bigger unit? Say I want to make an entire gallon of astronaut ice cream.
I would do as he said, realistically, the water chamber does not need to be that big. I would do a 3 gallon dryer, and a 2 quart water chamber.
Brilliant. Looking to make one, hopefully this gives me a better idea.
Can you just freeze the food first in the refrigerator freezer before putting it in the vacuum? Saving all this mess?
This was very helpful
I know this is 5 years later, but if I need to do vacuum steam distillation, can I use the same setup, but an induction burner to do 135 or so to boil off the water?
Why is the water trap necessary? Wouldn't the pump remove the water vapor anyway? I mean depending on your pump its probably a bad idea but that would depend on the pump...
one small point, don't use regular spray adhesive on polystyrene, the propellant and the solvent in in dissolves the polystyrene, same is true for a lot of plastics, you need the one that's specifically made for plastics though to pay through the nose for it
tigoda85, 3m brand super77 contains acetone, and that eats most foams. Yet if you take said adhesive and spray thin, light coat from a distance of 16 inches approximately on both surfaces to be bonded, it won't melt foam. Acetone evaporates before it reaches the surface. You'll tear the foam apart well before you tear the glue seam. Great adhesive for using a hotwire cutter on laminated foam
Do you need to keep the pump running once it has created the vacuum? Could you get away with putting the food into the vacuum chamber, bringing it to full vacuum and then sitting the chamber inside a freezer for a few hours until the food freezes and the water sublimates from it? The sublimation would create some pressure inside the chamber but if you kept the batches small it would just condense on the sides of the chamber as frost. As a note, I'm thinking about this from a food storage standpoint.
Ya you can't turn the pump off till it's done. It loses pressure very quickly the second you turn it off from the massive amount of water vapour coming off the items
any chance you can link to a pump? I know absolutely nothing about them so I can't tell a good value from not.
Had to rewatch this video again for cold trap inspiration... Do you think this design would work for capturing methanol/VOC's in a vacuum percolation device? I'll be bubbling humid air through distilled spirits to expedite oxidation reactions and simulate gas exchange in a barrel. I have access to a diaphragm pump (not PTFE.... But I want one someday...) that can go down to 27in Hg, and I don't want too many vapors to condense in the pump itself... Is there a cold trap design you'd recommend for the budget-conscious creator?
A 2 stage rotary vacuum pump that is 1hp 8cfm and has an ultimate vacuum of 0.3Pa should work well right?
Wow only 6 to 14 hours
AWESOME!!!
I understand how you built everything but i have no idea if the drying chamber and water trap are tied together??? I really want to copy your set up but im a little lost on the whole water trap.. If anyone could explain to me what I'm missing I would greatly appreciate it!! Does the drying chamber just sit in the water trap?
A question for the PhDs: I've watched snow sublimate in sunlight with temperature in teens, with concrete actually dry. Sometimes even 'steam' can appear. Snow in thin layer. Layers of snow actually also reduce without obvious melting (liquid). So can a freeze dryer be made say cooling down to 10F, with a sun lamp, in a very dry or vacuum environment?
Yes, that was my query too. Looking at the phase diagram for water, he actually made it harder to freeze dry by cooling to such an extreme and having such an extreme vacuum. The sublimation line stretches from zero pressure and absolute zero temperature to the triple point of water so really all that should be needed is keeping the temperature below the triple point (0.16C) by enough of a margin so there is no danger of liquid water forming and then having a partial vacuum, the higher the temperature, the less of a vacuum would be needed to sublimate the ice. I think he shot himself in the foot with this experiment.
Now rapid cooling of the product could help preserve the quality and texture so initial quick cooling with dry ice may be useful.
If I was to home dry freeze, I would quick freeze the product with dry ice then place it into mason jars, use a foodsaver jar attachment to create a partial vacuum. The foodsaver's pump can remove just less than half an atmosphere which should be enough if the temperature is high enough but you can use an automotive or AC vacuum pump including the hand brake vacuum pumps to remove 90% of atmospheric plus those pumps are intended for removing water vapour so a cold trap would not be needed to protect the pump. The automotive brake and AC pumps happen to use the same hose size as the foodsaver jar attachment. Then it's a matter of keeping the jars in the deep freeze with periodic vacuum draws for days. Weighing the jars would show you how much water has been removed and the USDA publishes a list of the water content of common foods. I suspect it would take days to weeks to freeze dry foods this way.
@@trevorfichtner3539 Well, it isn't just the vacuum that matters we just have the most data on temperature and pressure with phase diagrams, but it's the vapour pressure so to preserve the terpenes, I would suspect using zeolites to preferentially reduce the water vapour pressure as the air pressure is removed. Ideally a membrane could be used so that the vacuum drew out more water vapour than terpene pressure, you would still lose some, the hope is to remove less of what you want preserved. The water trap is cold obviously to condense as much of the water vapour as possible, it's like how a dehumidifier works, the evaporator is simply colder than what's being dehumidified. Obviously condensation isn't the only way to remove water vapour, you could absorb them instead again with zeolites, some silica gel packets can do a lot to help with your DIY home freeze drying (note again, though zeolites for selective absorption, they do absorb some of what you don't want absorbed, nothing is perfect). Short of finding the phase diagram for terpenes to see if there are any differences from the phase diagram of water you could take advantage of, the best course for home experimentation would of course be to just try a few variations and work out a systemic way of deciding which worked better. Terpene is presumably a complex organic compound so it may have a rather complicated phase diagram with some of it's components behaving differently than others so you also have the possibility of possible decomposition. Maybe you should try contacting commercial marijuana producers to see what they do, it's always best to survey what's already being done first.
Yeah snow can sublimate partly because winter brings low humidity and the crystals can be especially effected by sunlight. I don’t think the conditions of a freeze dryer would be as applicable, maybe it could help a bit tho. Worth a shot but you’d probably want the lamp inside the chamber and that’s a pain
@The Thought Emporium
I cannot stress how grateful I am for your work, My 13 year old is just finishing putting the thing together for me, obviously I will be connecting the VAC pump and operating the machine, thanks again. Have you ever thought of building an electron microscope (its been done before)
how would you know if the freeze drying process is complete without any sort of sensor and what is the max vacuum i should use for foods
When I was searching for DIY Freeze drying, I was really hoping I'd find a video that said -- "Stick desired freeze dried item in the very back of the freezer and wait"
could you recommend the cheapest vacuum pump capable of reliably achieving the level of vacuum required please
Go to Cody's lab and check the one he made powered by mercury, that should do the trick, it's really cheap as it has no moving parts and you get a free workout
@@moralesriveraomar233 awesome thanks man, greatly appreciated it needs a bit of work but looks good
i was looking for Harvest Right, then i find this video. thank u, sir.. i will try to make one . thank u.
bro i just wanted to freeze dry raspberrys not end up building a rocket 😂 Jokes beside, great Video 👍
Is the cold trap really necessary? It seems to me that it would only be needed to protect the pump from corrosive chemicals that would not be compatible with it's internals. I can understand that water vapor would physically mangle a turbo-molecular pump, but I would think a vain or diaphragm pump would be more robust. Is it just a case of it not being practical to make a pump that gets you to that level of vacuum and can handle some water vapor?
Over 20ml of water was in the cold trap when I let it thaw out, so ya it's super neccasary. The issue isn't the pump per say, that you're screwing with the oil in the pump which can then mess with the pump. Or if condensation is left inside the pump when it's turned off it'll rust internally
RRRRIIIGGGHHHHTTTTT. LOL I simply bought a Harvest Right home freeze dryer back in Dec 2081 - I run it almost 24/7 and have processed a lot of foods for long term storage. Compared to buying commercially produced FD foods - my dryer has paid for itself many times over. It will also process up to 20 pounds of foods in a single batch.
Good luck with your DYI dryer.
Nice gloves for the dry ice
And at 16 hours per cycle, to get a decent sized bag of freeze dried strawberries, it takes how long, a week?
Hi im wondering can.. flys be frozen and reanimated back to life?
Can anyone help me out with this? Do you put anything inside the cold trap or does it stays empty? Is that where you freeze the food or does the food has to be frozen first?