One question you probably won't get answered is, well, what the heck is ice cream? The Food and Drug Administration says it's a product made by mixing and freezing simultaneously a dairy product and protein with flavors and sweeteners. It needs to be at least ten percent milk fat and weigh at least 4.5 pounds per gallon. It can have other things like egg yolks, but if it's more than 1.4 percent egg yolk by weight, it's usually called "frozen custard." Variations like gelato and soft serve come from varying the proportions and preparations of the ingredients; gelato has less milk fat, and soft serve is prepared at a higher temperature.