I add the buttermilk powder to the dry ingredients and add water to the wet ingredients. The brand I have, SACO says for 1 cup buttermilk use 4 TBSP blend with.
Our dried buttermilk powder is ideal for baking; simply use 1 part powder to 4 parts Tired of buying a quart of buttermilk when you really only need half a cup?.
Ingredients: A cultured blend of sweet cream churned buttermilk, sweet dairy whey, and lactic acid. Easy to use and easy to store, the convenience of our unique powder mix makes it easy to enjoy. Our natural conversion table- buttermilk.