Cultured Butter

Cultured butters are a lot like sweet cream butters, save for the fact that they’re made with cream that’s been allowed to ferment slightly. Lactic acid go to work on the sugars in the cream, digesting them and creating a variety of by-products including acetic acid, acetoin, ethyl formate, ethyl acetate, 2-butanone and especially diacetyl. The effect of those by-products is to heighten the flavor of the butter, in much the same way a starter heightens the flavor of bread.