I'm wondering why don't more recipes use yolk weight or yolk/white ratio in their description to get a more precise result? Things like flour/sugar have very precise weights listed, why not eggs?
Is that the case in pro-baking circles?
1 Answer
For modern recipes:
Because eggs get sorted by weight and classified before they reach supermarket shelves. That means within the acceptable deviation stating a number of eggs is perfectly fine.
The international baker however will need to consider that eggs sizes are different in different regions of the world and may need to adjust slightly, for example where a US recipe calls for size L eggs, an European M will be better.
If you have very finicky recipes, even modern recipes will start with weighing the eggs or egg whites and then base the other ingredients on that value. Today, many macaron recipes are a good example for this approach, but there are others, like Victoria sponge.
This is based on more historical recipes, when cooks had to make do with whatever eggs they had on hand and on a farm, their weight can differ greatly. I have a few old cook books that will for example call for 4-5 eggs, and the experienced cook or baker will choose according to egg size. There’s also often some wiggle room, like adding a splash of other liquid to a too-dry batter if the eggs were a bit small or scarce.
In a commercial setting however, eggs are listed in weight, just as all other ingredients. This is because for a large number, a deviation of a few grams per egg does add up to quite a lot and because in commercial bakeries and kitchens, eggs are often either bought already cracked (and separated, if applicable) as convenience products, or get separated at a different workstation just like for other prep tasks.
