residue from making butter from sour raw milk; or pasteurized milk curdled by adding a culture
buttermilk详细解释
but.ter.milk n.（名词）The sour liquid that remains after the butterfat has been removed from whole milk or cream by churning.酪乳：将乳脂从牛奶或一次提制的奶油中除去之后剩下的酸味液体A cultured sour milk made by adding certain microorganisms to sweet milk.酸奶：在甜牛奶中加入某种微生物制得的发酵的酸味牛奶
