Bring kefir to room temperature. Bring the temperature of baked milk to 80C/175F, add kefir, stir, cover with lid, and let the mixture curdle for about 15 minutes. The cheese curds will be small and fluffy, the whey — milky.
Strain the whey using multiple layers of cheese cloth or unscented paper towel. Transfer the cheese into a closed container and store refrigerated for up to 1 week.
To serve, scoop a portion and form a ball with your hands. Baked milk soft cheese pairs well with crunchy praline and baked apples.