by Maggie Koerth-Baker
Sodium acetate is such a useful little chemical. Not only is it responsible for the awesome flavor of salt and vinegar potato chips, but it also produces the heat in those little reusable hand and foot warmers you can buy at outdoor stores. Plus—when it's just too damn cold outside and you'd rather spend the day indoors—the same reaction that keeps your fingers and toes toasty can also be used for fun at-home art projects.
You can buy sodium acetate online, but all the real Cool Kids are making it themselves .
I came back to my dorm from spring break or something and when I took my full brita pitcher out of the fridge it did the exact same thing as the first experiment. I stood there complete dumbfounded as the entire thing slowly froze solid. I was the first person back from break so nobody was there to show. I wonder now if someone slipped some sodium acetate in it or if there was some weird cross contamination with chips or Boston's water.
Considering that salt is sodium chloride, and vinegar is acetic acid, it is pretty obvious that the flavor of salt and vinegar potato chips is from sodium acetate. But that sounds so much scarier than "salt and vinegar", doesn't it? It's like Japanese seaweed extract. If I tell you that that Japanese have used this natural substance to flavor their food for centuries, it sounds charming, doesn't it? If I tell you that this extract is technically monosodium glutamate (MSG), it sounds all chemical and scary.
the rapid solidification process occurs through what's called homogeneous nucleation. the solution has been supercooled. it was poured very gently into a smooth walled container. this allowed the solution to remain supercooled. upon touching the solution the rough ridges in your fingers, the slight increased temperature and the impact of touching it create nucleation sites. This solidifies the solution near your finger and then creates more nucleation sites and the solid grows out like a dendrite.
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