Milk kefir is an easy sell for anyone who loves yogurt, which I most definitely do. Kefir is tangy, about as thick (and creamy!) as a smoothie, and full of those good-for-you probiotics we hear so much about. Think of milk kefir as drinkable, pourable yogurt. Even better, you can skip the grocery store and make it yourself right on your kitchen counter.
Fresh milk kefir, strained and ready to drink
What Is Milk Kefir?
Milk kefir is a fermented dairy product similar in many ways to yogurt and buttermilk. It's how kefir is cultured that makes it really unique — instead of heating the milk, adding a culture, and keeping it warm as you do with yogurt, all you need to make milk kefir are kefir grains.
Kefir grains are not really grains at all (don't worry, gluten-free folks!). These "grains" are actually tiny, rubbery, knobby-looking cell structures that are home to the bacteria and yeast that ferment the kefir. These grains are the milk kefir equivalent to the scoby used to make kombucha.
How Does It Work?
It's extremely simple. Add about a teaspoon of these kefir grains to a cup of milk, cover the glass, and let it sit out at room temperature for about 24 hours. During this time, the healthy bacterias and yeast in the kefir grains will ferment the milk, preventing it from spoiling while transforming it into kefir.
When done, the kefir will have thickened to the consistency of buttermilk and taste noticeably tangy, like yogurt. Strain out the grains so you can use them in another batch, and the kefir is ready to drink.
Oh, that's another thing! As long as they stay healthy, you can reuse kefir grains indefinitely to make batch after batch of kefir. And the best way to keep them healthy is to keep making kefir! You can make a new batch of kefir roughly every 24 hours (the temperature of your kitchen can affect the exact time) just by putting the kefir grains in a fresh cup of milk. Over time, the grains will multiply and you can either discard the extra or share it with friends. You can also take a break from making kefir by putting the grains in a new cup of milk and storing this in the fridge.
Are There Health Benefits?
Yes! Like yogurt and other cultured and fermented products, milk kefir is full of probiotics, which aid healthy digestion. The fermenting process also changes some of the protein structures in the milk, making it easier to digest. Some people who can't tolerate milk often do better when drinking milk kefir.
What Milk to Use?
The kefir grains work best with whole-fat animal milk, which is to say, whole fat milk from cows, goats, and sheep. You can successfully make kefir with 2% and reduced fat milk, but if you notice that your grains are behaving sluggishly or taking longer and longer to ferment the milk, pop them back in a jar of whole milk to refresh them. You can also use raw or pasteurized milk, but avoid ultra-high temperature (UHT) pasteurized milk.
If you're looking for a non-dairy option, try making the kefir with coconut milk. Since coconut milk lacks the same proteins and nutrients as animal milk, the kefir grains will lose their vitality after a little while. To refresh them, put them back in some animal milk for a batch or two. Unfortunately, I haven't had success with making milk kefir with almond milk, soy milk, or other dairy-free milks.
What Can I Do With Milk Kefir?
You can drink milk kefir just as it is, straight-up! You can also add milk kefir to smoothies, lassis, and other drinks just as you would use yogurt or regular milk.
Kefir is fantastic for baking, too! Use it in place of yogurt, milk, or buttermilk in any recipe you make.
Is This Safe? What Can Go Wrong?
The practice of making milk kefir has been around for several thousands of years, and was traditionally a way of preserving fresh milk and making it last longer. This is to say, yes, it's safe. The healthy bacterias and yeasts in the kefir grains box out any unhealthy or spoiling bacterias that would otherwise take hold of milk left at room temperature.
I've been making milk kefir for years now, and the only real concern I've run into is room temperature. Kefir grains like an average room temperature of about 60°F to 90°F. Below 60°F, the grains become sluggish and can go into hibernation — they're still fine, but it might just take longer to make the kefir. Above 90°F, the milk spoils more quickly than the grains can culture it, and this creates an unsafe environment for the grains (and you). Avoid making kefir on very hot summer days if you don't have air conditioning.
Also, be sure to make your kefir in a glass jar as the grains can become weakened by exposure to metal. Brief exposure, like using a metal strainer or stirring with a metal spoon, is fine.