Sour Milk Substitution

Soured milk is a food product produced from the acidification of milk. Acidification, which gives the milk a tart taste, is achieved either through the addition of an acid, such as lemon juice or vinegar, or through bacterial fermentation. Lactic acid bacteria feed on the lactose found in milk. As the bacteria feeds on the lactose, it breaks it down into lactic acid which is released into the milk. As more and more lactic acid is produced, the milk becomes thick and turns into sour milk. The lactic acid inhibits the growth of harmful bacteria and thus improves its shelf life.

In older recipes that call for sour milk the term refers to milk that was not consumed before it went sour. Prior to refrigeration, this was a common occurrence. Sour milk is NOT the same as spoiled milk that has gone bad and which may contain toxins. Store-bought, pasteurized milk doesn't sour; it just goes bad. Sour milk is raw milk that was not used quickly enough.

Acidified milk, milk that has had an acid such as vinegar or lemon juice added to it, can be substituted for sour milk but it is not the same thing. Today with modern food safety ideas, it is not considered safe to drink sour milk, but it was commonly used in cooking which would have killed any bacteria present.

Substitutions

If you have a recipe that calls for sour milk you can add a tablespoon of vinegar or lemon juice to your milk and allow it to sit for 5 minutes.

Alternately allow raw milk to sit at room temp for 12-14 hours or use buttermilk, which is similar to sour milk.