1 litre pasteurised or raw cow’s or goat’s milk
3 tbsp kefir grains
If using pasteurised milk, bring the milk the boil in a pan, stirring occasionally. You need to bring
the milk close to the boiling point in order to destroy any bacteria, which may linger in the milk
and interfere with the fermentation. However do not boil the milk as it will change its structure
Take the pan off the heat. Cover the pan with the lid and cool down by placing the pan in cold
water until the temperature of the milk is around 40-45 degrees. If you do not have a suitable
thermometer use your own hand to determine the right temperature. To do that take a teaspoon
of milk from the pan (using a clean dry spoon) and put the milk on the inside of your wrist. If it
feels just slightly warm then the temperature is just right.
If you are using raw organic milk, which has not been pasteurised or processed in any other way,
you don’t need to heat it, so you can just skip this step. Keep in mind though that raw milk has
got its own bacterial population, so the fermentation is not going to be as controlled as with using
heated milk. That means that your kefir may turn out to be more liquid, lumpy or sour. If you
can only accept a certain consistency of kefir, then heat the raw milk close to the boiling point
to make the fermentation more predictable.
Gentle heating at home is not as destructive for the milk as commercial pasteurisation: it will kill the bacteria and change some things in the milk, but not as badly as commercial treatment.
Ferment the kefir for at least 24 hours or longer.
After the fermentation is complete, use a non-metal strainer and separate the kefir grain from the kefir. Move your kefir to a clean, dry glass jar and place the kefir grains in a new jar to start a new fermentation process.
You now have an option to double ferment the kefir by adding a slice of fruit, a cinnamon stick, or a vanilla pod, and leaving it out covered with a lid for a further 1-4 hours.
Once you have completed the first fermentation or the double fermentation process, refrigerate the kefir and start the process again with the leftover kefir grains.
Your kefir grains will continue to grow as long as you keep feeding them with fresh milk. If you are going away you can store your kefir grains in some milk in the fridge. Make sure you have sufficient milk to keep the kefir grains alive. They may be a little unhappy once you return but after a few batches will rehydrate and make delicious kefir again.