Nucleation and crystal growth

How do you make rock candy and chocolate fudge? What makes one sugary sweet hard and crunchy but the other soft and chewy? Cammie provides an answer through a discussion of nucleation and crystal growth.
MATERIALS SCIENCE TETRAHEDRON:
Curious about the materials science tetrahedron? Watch this video to learn more: • What is materials scie...
OUTLINE:
0:00 Introduction
0:24 Ming’s fudge conundrum
0:43 Crystalline materials
1:21 How do crystals form?
2:02 Making rock candy
3:31 Homogeneous nucleation
4:35 Heterogeneous nucleation
5:41 Distribution of crystal sizes
6:30 How to prevent grainy fudge
CREDITS:
Written, presented, and edited by Camille Farruggio and Mingyu Yang
With additional input from Ethan Rosenberg, Robin Lindemann, and Jacqueline Baidoo
ACKNOWLEDGEMENTS:
We are grateful for the support of the MIT Department of Materials Science & Engineering (dmse.mit.edu) and Dr. Rohan Kundargi, K-12 Outreach Coordinator of MIT's Office of Government and Community Relations.
ACCESSIBILITY:
[e-mail]
CONTACT US:
If you have a food/materials-science question that you’d like to see featured in a future video (maybe even with you in it!), please reach out at [e-mail]. You can also keep up to date on Twitter @foodsci_mit.

[@adamkhali8988]

Hi im french and i want say to you :thanks a lot

[@pavanpujar7100]

Very nice video.. I am a Ph.D. in Materials Engineering. I enjoyed every bit of the video.

[@xXBLAKGOATXx]

Head up your audio cut only to the left channel on your output for like 7 seconds 6:07

[@angelaseifert6202]

You guys are awesome! I've read my notes countless times, watched so many videos, and read so many articles online but I could not understand the process of nucleation for the life of me. You guys helped so much, especially with the cooking and lego analogy.

[@kitchenmatters7927]

Reading comments like these genuinely makes me so happy :) I am so glad that recontextualising these materials concepts to food and cooking has helped to make it click. The lego analogy was all Cammie's idea, and I also think it was very clever. Thanks for leaving the kind note - Ming

[@flamesp1798]

I'm taking material science course this term.. and I could not understand the professor's explanation regarding nucleation and growth. But this video REALLY helps me to understand it. THANKS! I really appreciate your effort on making this video... and really love the lego analogy btw xD

[@kitchenmatters7927]

I'm so glad that this video helped to make it click! The lego analogy was all Cammie's idea, and I think it's rather clever. Do email us at [e-mail] if you have other ideas about how we could explain difficult concepts through the lens of food :) Good luck with the rest of your class! - Ming

[@roamingdev]

I know this is a material science channel but boy can it be a cooking one as well teaching the "why" and the underlying principles that most other coocking channels miss.

[@kitchenmatters7927]

Yes, that really speaks to the very reason we launched this channel! Food is a wonderful lens through which to elucidate materials science principles. I'm glad you enjoyed learning the "why" underlying the recipe. - Ming

[@user-jv4xy9un9l]

amazing video so super easily understood thank you!

[@lindokuhlemdz8350]

Best video ever!!! the examples are so easy and makes the whole thing easier! well done, I respect you guys!

[@kitchenmatters7927]

That is very kind of you, thank you. I passed on your message to Cammie, and we're both delighted that you enjoyed the examples. - Ming

[@irfanafzal2215]

informative and nicely presented.

[@tjhika]

thank you! your video really helped me to understand nucleation

[@WolfgangDibiasi]

well explained

[@amaliamartins9584]

More videos!

[@valerieconrad1005]

Great video! My 8 year old son asked why our honey had solidified. Your lego analogy really helped him understand! And know I have a better idea on how to make smoother fudge!

[@kitchenmatters7927]

Awesome! That lego analogy was all Cammie's idea; I think it's really clever! We're about to release another video this Friday about the science of caramel, which extends the analogy a little further. Wishing you and your son many more food science discoveries :) - Ming

[@kartikchopra3131]

This was really awesome.!

[@kitchenmatters7927]

Glad you enjoyed it!

[@howvery2043]

SO SO HELPFULLLL

[@amartini51]

Sugar is one of my favorite crystals too!

[@bellamiss341]

Hi, can you explain toffee separation with butter in science? Thank you.

[@HenriFaust]

Isn't it a bit pretentious to call freezing solidification?