Ice cream - why yolks but no whites?
When making a custard based ice cream, all the recipes I've seen require egg yolks, but no egg whites. I was getting a bit curious about this: Why do we need to remove the egg whites? They're just a tiny amount of water and some proteins, right? I assume the water can't be any problem, so if anything it has to be the proteins. But exactly what kinds of problem will I get if I keep the whites in the mix? Wouldn't the egg white proteins act as a kind of stabilizer, making my ice crystals smaller and the mix viscous?
"When making a custard based ice cream, all the recipes I've seen require egg yolks, but no egg whites."
You've answered your own question; because you ar making a "custard" based ice cream. By definition, a custard is a variety of culinary preparations based on a cooked mixture of milk or cream and egg yolk.
There are ice cream recipes that call for whole eggs; they are not truly "custard based."
That is not true.
Custards can be made with whole eggs
Custard is a culinary preparation made by blending eggs with milk or cream. Custard is thickened by the coagulation of the egg proteins, which is achieved by gently heating the custard in some way.