May 21, 2016 at 06:23AM

Today I Learned: 1) Not all gel-staining dyes go in the gel... some are meant to be added after the gel is run, by soaking the gel in the dye. 2) Solid chocolate has at least five different crystal types! The different crystal types represent chocolate in different molecular arrangements. Much like metals, which have different temperments depending on how they're heated, worked, and cooled, chocolate can take on different crystal structures, giving it different properties, depending on how it is handled. Type I and type II chocolate crystals are the highest-energy (least stable) chocolate forms. They are very soft and melt easily. That's not good for most chocolate applications, but it *is* good on cold things like ice cream, as it will melt more easily. If you eat ice cream dipped in chocolate, you probably want it dipped in type I or II chocolate. Types III and IV chocolate are moderate consistency and moderate melting temperature. These types are kind of crumbly, and don't produce a very satisfying snap, but they're reasonable for most applications and are the easiest forms to make -- they aren't as low-energy as type V chocolate, but if you cool chocolate under most conditions it will be kinetically trapped in type III or IV. If you leave type III or IV chocolate for long enough, it will slowly convert to the more stable type V, but this process excludes fats and some other molecules (type V effectively is less soluble to fats), which is why some chocolates will "sweat" if stored long enough. Type V chocolate is, most often, what chocolate makers aim for. Type V is very stable, and thus breaks with a highly satisfying snap. It also has a fantastic melting temperature of about 93°F, which means it will only really melt when you eat it or if it's hotter outside than you are inside. The melting process also absorbs heat, which supposedly gives type V chocolate a cool sensation. I'll be on the lookout for that effect next time I eat some good dark chocolate. The only real downside to type V chocolate is that it's hard to make. The standard way to make type V chocolate is to seed a molten chocolate mix with crystals of type V, which nucleates the production of more type V and, if done correctly, outcompetes the production of types III and IV. 3) Still on the topic of chocolate, did you know that coca pods are fermented before being processed into coca powder? Specifically, they are husked, piled up on the ground, and left to rot for a while. Fermenting chocolate is a bit like fermenting wine -- the exact conditions of fermentation determine the flavor of the chocolate, and chocolate made with specific techniques from specific places is highly valued among chocolate manufacturers.