Milk kefir is the easiest ferment to learn. You need live kefir grains, milk and a clean glass jar. Add the grains to the milk, wait about a day, strain and drink. The grains go straight into the next batch, so one set keeps making kefir for a long time when you look after it.
Takes 12–24 hours
You’ll need
- 1 to 2 teaspoons of live milk kefir grains
- Up to 1 litre of full-cream milk
- A clean glass jar
- A plastic or nylon strainer (stainless steel is fine too)
- A wooden or plastic spoon
- A coffee filter or tight-weave cloth, and a rubber band
Which milk should I use?
Fresh full-cream milk from the dairy is fine once it is boiled and cooled below 30°C. Packet (UHT) milk works for a batch or two and is a handy backup, but for daily feeding use pasteurised milk or boiled fresh milk. Avoid flavoured milk and tea whiteners. Goat’s milk gives a thinner kefir. Buffalo milk gives a very thick one, so thin it with a little cow’s milk or water if you like.
Method
- Prepare. Wash your hands and the jar. If you use fresh milk, boil it and let it cool until it is lukewarm or cooler.
- Mix. Put the grains in the jar, pour in the milk and stir with a wooden or plastic spoon.
- Cover and wait. Cover with a coffee filter or cloth and a rubber band. Keep it at 20 to 29°C, out of direct sun. In very hot weather use fewer grains, choose the coolest room and check from 6 to 8 hours.
- Check. At about 12 hours it is thin and mild. At about 24 hours it is thicker and tangy. By 48 hours it splits into curds and whey.
- Strain. Pour through the strainer into a bowl. Put the grains straight into fresh milk for the next batch.
- Store. Keep the kefir in a clean jar in the fridge. It tastes best in the first week and stays good for 2 to 3 weeks if kept cold.
Want more flavour? Leave the strained kefir out for 6 to 12 more hours with a cinnamon stick, a drop of vanilla or a strip of citrus peel, then take the flavouring out and chill it.
Troubleshooting
- Too thin? Give it longer, or use full-cream milk.
- Separating into curds and whey? It cultured too long. It is still fine to drink: whisk or strain it. Next time use less grain, more milk, a cooler spot or less time.
- Fizzy or yeasty smell? Normal, especially in hot weather. If it smells pleasantly sour and looks clean, it is fine.
- Grains not multiplying? Grains often take 6 to 8 weeks to start growing, and some never grow much. They still make kefir.
- Mould? White, green, orange, red or black fuzzy spots, or pink patches, mean you should throw away everything, grains included.
Going away? Put the grains in 2 cups of fresh milk, close the lid and keep them in the fridge for up to 3 weeks. For longer, rinse the grains, dry them on parchment paper for 3 to 5 days and keep them in an airtight bag in the fridge for up to 6 months.
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