Homemade milk kefir is not only brimming with minerals, vitamins, amino acids and enzymes, but also probiotics and beneficial yeasts. And the best bit? The end product is virtually lactose-free, as the grains digest it for you! —Emma Galloway | My Darling Lemon Thyme
Pour the milk into your glass jar and add the kefir grains. Cover the top of the jar with muslin and secure it in place with a rubber band. Next, place the jar in a dark place (I put mine in the pantry), and leave it for 12 to 24 hours, until you see that the liquid is beginning to separate into curds and whey.
Keep in mind that the mixture will ferment quickly in the summer , but at colder temperatures, this process will take longer. Avoid making the kefir in rooms hotter than 90° F; at this temperature, the milk might spoil before the grains can culture it.
After the mixture has been sitting, pour the entire contents of jar into a plastic sieve placed over a bowl. Gently shake the sieve from side to side to encourage the kefir to drain through. If I have left the jar a little bit too long and really solid bits have formed, I let the sieve rest in the bowl of drained whey. I mix the solid parts gently back into the grains until the really firm curds are loosened, and then I re-strain the liquid.
The strained kefir is then ready to use. Drink it plain or sweetened, or use it in place of milk, yogurt, or buttermilk in your baking and cooking. It can also be stored in the fridge for up to a week.
Then, use the strained kefir grains to make your new batch in a clean jar. There's no need to rinse the grains between batches.
You can make as little or as much kefir as you want: I usually make 1/2 liter every other day. If you want to slow things down a bit, let the mixture ferment in the fridge instead of in the pantry.
If you only have a tablespoon or two of grains to begin, just use a cup or two of milk until your grains have multiplied enough to ferment more milk.
Excess kefir grains can be frozen: Rinse them well, pat them dry on a clean cloth, coat them lightly in in milk powder, and then freeze them in a double-lined plastic bag. Keep in mind, however, that frozen kefir grains may take up to three months of fermentation before they produce consistently good batches of milk kefir.