How to make Milk Kefir
Milk kefir is a fermented probiotic-rich drink that helps restore and maintain a healthy gut microbiome, essential for optimal health. It's an especially powerful probiotic in terms of the variety and number of bacteria it contains, much more potent than other probiotic drinks such as Kombucha or yoghurt.
It is ideal to make it yourself at home rather than buy it from the supermarket. Homemade kefir is vastly superior in terms of its nutrition and probiotic value than the standard supermarket stuff. That said, some farms do sell high-quality kefir.
All you need are milk, and milk kefir "grains" - not grains in the literal sense, but blobs of bacteria and yeast. The microbes from these grains eat the lactose (sugar) in the milk and ferment it. The grains grow and multiply over time and you re-use them with each ferment.
You can buy organic milk kefir grains online and have them delivered to you in most countries. Make sure they are organic and don't buy water kefir grains by accident (water kefir is a different drink).
The milk you use needs to be as high quality as possible. Usually people use cow, sheep, or goat's milk. The ideal is raw organic grass-fed milk from a healthy animal. By raw I mean the milk should not be pasteurized or homogenized, processes that damage the nutrients and natural bacteria in the milk. Absolutely bare minimum, the milk must be organic and unhomogenized.
Note that coconut or other plant milks are not suitable for making milk kefir, they do not contain the nutrients needed for the grains to survive and multiply.
If you get kefir grains shipped in the mail then you definitely need to do this. The grains will be dehydrated and dormant, having not been in milk for some time, and in need of "re-activating". Put the grains in a bowl of milk (around 250ml of milk or so) and leave it at room temperature for 1-2 days at room temperature. Cover it with something such as a cloth or paper towel. I use a paper towel with an elastic band to hold it onto the bowl. When the milk starts separating, the grains are ready. If there's no separation for 2 days, you can strain out the milk and replace it with new milk, and see if there is any separation after another 1-2 days.
Milk kefir may go through one or two stages of fermentation before you drink it.
For the first fermentation, place your grains in a glass bowl or jar and add milk. Many suggest using 250ml of milk for every 5g of kefir grains, though I have deviated a bit from this guideline without issues. Then cover the bowl or jar with a cloth or towel and leave it for 1-2 days. In hot climates the fermentation may only take 12 hours or less. It's a good idea to stir the kefir occasionally too.
When the ferment is done you'll see the kefir grains floating at the top of the milk, the milk will look thicker, and you'll see some separation of curds and whey. Strain out the milk into another bowl/jar, separating it from your grains. You then reuse the grains for another first ferment. By now it's likely the grains have grown and multiplied somewhat.
You may drink the milk you just strained out, or refrigerate it to drink later. Alternatively you may do a second ferment with it.
The second fermentation further increases the kefir's bacteria count and nutritional value.
Put the kefir milk taken from the first ferment into a glass container. Cover it and leave it for 12-24 hours, though again in a hot climate it will ferment quicker, perhaps in 6 hours. Unlike the first ferment, I usually do the second ferment anaerobically by putting the milk in a sealed jar or bottle, carbonating it a little. However this is totally optional and if you don't want to risk an explosion then you may do the second ferment aerobically like the first one.
You may also put some sliced fruit into the milk for the second fermentation, to add some extra probiotic value and flavour. For milk kefir, I like to add some chopped blueberries.
When the second fermentation is done, the milk will have heavily separated, like a large white blob sitting on top of a layer of clear pale liquid. You can stir it up or even put it in a blender to create a consistent texture. Drink it straight away or you may refrigerate it for later.
Dos and Dont's
Keep the grains and milk in glass containers, not plastic or metal ones. Exposure to plastic or metal for long periods may damage the grains and bacteria.
Don't wash the grains, this will damage them. Keep them and the milk outside of sunlight too, otherwise unwanted bacteria and pathogens may start growing.
Milk Kefir is very resilient to contamination, but it is good to check for any obvious signs of mould. If you find any you should probably ditch your grains and buy another set. After months of fermentation mine never went mouldy, but you never know.
If you have any excess grains, you can eat them for a little extra probiotic benefit.
If you're going away and not taking your grains with you, or want to take a break from making kefir, put your grains in a large bowl of milk and store it in the fridge for up to one month.