Prepare 4 cups,
The first glass is poured into the store buy milk.
The second poured into the store buy milk and add a teaspoon of sour cream.
The third glass is poured into a home milked milk.
The third glass is poured into a home milked milk and add a teaspoon of sour cream.
After two days it determines what changes have taken place in the glasses, the tasting.
We conclude that the lactic acid bacteria 2 glasses are savairojušās. Guess - where?

Enjoy your meal!