Can I substitute water for milk, in....
..recipes for baked goods like cakes, cupcakes, etc? For that matter, what about using thinned-out yogurt (with a bit of extra sugar to offset the sourness) instead of milk?
There's a recipe for chocolate cupcakes I'm thinking of making. It wants 1 cup of milk, but no one in the house uses milk. Can anyone make an educated guess about the effects of substituting water for milk?
I'm guessing that one purpose the milk serves is that it provides a bit of acidity for the baking soda (as well as baking powder) that the recipe uses.
There is also a bit of sweetness in milk and a bit of fat, which both affect the body of the end product. I always keep dry powdered milk in the house for use in baking. It's skim powder, but still adds the body to the product. I wouldn't use water. A bit of thinned out yogurt would be fine in most, I would think. I wouldn't add extra sugar though. There is probably enough sugar in the recipe already.
I think using water instead of milk would affect the outcome. Milk has properties like proteins and sugars that would contribute to the chemical reaction of the ingredients. I would think things like leavening would be effected.
The milk is not essential in many, if not most, cakes. There is, for example, a 'crazy cake' that just uses water, oil and vinegar as the liquids. People also substitute soy milk, rice milk, etc for milk.
The cake already has a lot of sugar, fat too. The egg yolks also provide fat. As for protein, the eggs whites have that. Milk only add acid if it is buttermilk or yogurt.
We don't drink much milk, but I keep some Nido whole dried milk on hand for baking. If the recipe calls for milk, I may add a couple of tablespoons of the powder to the dry ingredients. I don't think there's any advantage to premixing the milk.
Most of the "crazy cake" recipes I've read use a boxed cake mix as their foundation and boxed cake mixes typically contain powdered milk products. I'd suggest you follow the powdered dry milk suggestions and keep it on hand. Mix it according to package directions and use it just like you would regular milk. Adding a bit of yogurt, sour cream, etc. to your prepared powdered milk is OK, just don't overdo it.
Consider using rice mylk or almond mylk. We're vegan so we use plant-based mylks in recipes and on cereal. If something calls for buttermilk you can just add 1 tsp of apple cider vinegar per cup of rice or almond mylk.
I drink milk, but use whole milk for baking, which I don't drink. I just buy a pint or half-pint, which they have at grocery stores with the other milk. Usually, with the chocolate milk, they have little bottles of chocolate milk, and they usually have plain milk, too.