ice cream

Why is a quick churn at -321F create smaller ice crystals than a typical slow churn at ~30F?

>>8838899
What in the fuck does that F stand for? Failed unit?

>>8838943
fahrenheit
-320.5F or -160C is the temperature of liquid nitrogen.
You take the ingredients (milk fat and it's liquids, sugar (sucrose), and flavorings) and freeze them to make iced cream. Normally it's done slowly with consistent churning to make the ice crystals small...I guess.

File: Kids.jpg (287KB, 879x617px) Image search: [Google]

287KB, 879x617px

I'm doing this for kids.
Think of the children.
Really, they're getting free ice cream, but it would be nice if I could foil it with a bit of science. Just to make it taste less sweet.

Well, I know it was a long shot asking here.
I've tried to educate myself in food related science a la Food and Science Lectures from Harvard who are graciously sharing information.
The science of it might be more interesting to some here.
https://www.youtube.com/watch?v=_Ft0cwxjBKE

>>8838899
https://en.wikipedia.org/wiki/Grain_growth#Ideal_grain_growth

>>8839068
I appreciate it, but it's over my head.
As a chef by trade, I struggle with hydrocolloids.
Wish I would have taken my chemistry courses seriously.

>>8839096
Lower temperature > less crystal boundary movement > more time until crystal grow very big

basically the grain boundaries of the small crystals thermodynamically prefer to be in larger crystal formation.
This forces the larger crystals to push their boundaries through the smaller crystals making even larger crystals.

I'd be okay if someone who actually understood metallurgy corrected me.

>>8839122
OP
It makes sense to me as a layman. The reason why you churn (slowly turn) Ice cream at a low temp is to stop it from forming large ice crystals.
If you just took the fat and sugar and h2o and put it in a 30F/0C environment, it would freeze and have large ice crystals, right? The h20 would separate and freeze on its own (kinda) and have large ice crystals unincorporated with the fats and proteins and sugars, right?

>>8839308
So if you're mixing it in a free-standing mixer and adding liquid nitrogen, you would be creating even smaller ice crystals incorporated with the fat et al?

>>8839308
The colder your working temperature, the faster you will have to churn to spread the temperature out evenly. You mention 30°F which is.... way too warm... You probably have to churn that very slowly so the thing actually freezes. I make mine at like 0°F, churning at a decent speed, probably 60rpm or something. The faster the whole process the better, because yes, crystals grow with time. Be careful not to churn too fast as to essentially whip the mixture because you will introduce air.

>>8839341
>Be careful not to churn too fast
Because then we'll be making a foam, yes!
I was just throwing out a temp when I said 30F. It is way too warm and really not even a good holding temp. Mea culpa.
I did do a test run yesterday. I didn't add enough liquid nitrogen, so it was kind of like soft serve, but it was really good. Looking forward to doing it later today. There should be some nerds in the crowd who can talk about soft matter science -"[the] ambiguous states of matter, the paradoxical properties of which rely on the art of mixture." -Pierre-Gilles de Gennes
Or some shit.

>>8839308
>h20
Hold the fuck on. Where did you get the H[math]_{20}[/math] from?