"Oh, I have something to give you," my good friend remembered at the end of a fun-filled evening with the kids — and considering good conversation is her love language and gift-giving usually isn't, I was really quite curious. A few seconds later, she produced a glass jar filled with white stuff.
Before I go any further, I'll tell you that people who use kefir grains to make kefir at home can come across as folks trying to sell you Tupperware or Avon, enthusiastically "recruiting" new members to their "multilevel marketing scheme". Except they do it because kefir grains proliferate like hell and they hate to see them go to waste, and if you accept the scheme, you (typically) don't have to pay money. All it takes is some milk and a little bit of work each morning (or other time of the day, but we'll get to that later). Before you know it, you'll be the one trying to bring new folks into the fold. In the meantime, though, you may be a little skeptical, a little worried you won't be able to keep your kefir grains alive, and a little unclear about what kefir and kefir grains actually are.
Kefir And Kefir Grains: What Are They?
The cottage-cheese-looking stuff collectively known as "kefir grains" is a symbiotic and relatively stable culture of yeasts and friendly bacteria mixed with proteins and sugars. Individual colonies of kefir grains will have different bacterial compositions, but Lactobacillus species are always involved. That's lactic acid bacteria. Kefir is the yogurt-like probiotic drink you get after fermenting milk in kefir grains and straining it into a cup through a strainer. The word itself is said to come from the Turkish word "Keyif", meaning "feeling good". 
Why Drink Kefir?
In short, 'cause it really does make you feel good. While it's an acquired taste for some, it's certainly healthy. Kefir promotes digestive health (including in people suffering from gastrointestinal disorders), reduces flatulence, reduces cholesterol levels, aids immune-system functioning, and even has anti-tumor properties. [2, 3] Doctors have additionally recommended kefir for hypertension, allergies, and ischemic heart disease historically, particularly in the Soviet Union . Kefir can also encourage weight loss , something that will appeal to many otherwise healthy people who would like to lose a few pounds.
Lactbacillus species don't come with adverse health effects , and not only is kefir suitable for many people suffering from lactose intolerance, it has actually been found to improve lactose digestion .
How To Look After Your Kefir Grains
To illustrate what I mean, I'll share the instructions my friend offered and implored me to follow when I first got my kefir grains:
- Your kefir grains go into a jar which you cover either with a lid with breathing holes or with cheesecloth. Both the strainer and the spoon you use should be made of plastic, since kefir grains die when they touch metal. The jar itself can be made of plastic or glass. Should your lid be made of metal, make sure no contact between the lid and your kefir mixture occurs.
- You add full-fat milk to your jar with kefir grains, after which your drink ferments for 24 hours, ideally at room temperature in a kitchen cupboard where it won't be exposed to direct sunlight. My friend told me that it was quite important to strain the kefir grains out of the milk in the morning at roughly the same time she did, because of this 24-hour cycle. (This 24-hour cycle really is a thing, by the way .)
- To strain your kefir properly, hold the strainer over your mug or cup and rotate your plastic spoon inside it (as if mixing sugar into a cup of tea) until the grains stay behind and the kefir is in your cup. Repeat as many times as possible and set the kefir grains aside on a saucer (again, no metal) in the meantime. After straining, thoroughly wash the jar but not the kefir grains themselves, and return the grains to the jar, then add new milk.
- Since it is very hot where we live in summer, my friend also told me to allow my kefir to "sleep" in the fridge overnight.
I've since read countless blogs on which people with kefir grains also describe the same process, but often slightly differently. Some will tell you to use skim milk, for instance, while others are going to say your kefir grains will perish if you do. Some will tell you plastic jars are bad, while my friend said plastic jars are the best (because they don't come with metal lids). Some will advise you to use a kefir grains to milk ratio of 1:7, while others advise 1:15, and some, like my friend, will tell you to just fill the jar up nearly to the top. I've also noticed some people saying that putting your kefir mixture in the fridge overnight will cause your kefir grains to go bad. Some will advise you to wash your kefir grains with water, while others warn that your tap water is probably chlorinated and this will kill your kefir grains. (You ddo not need to rinse your kefir grains, but if you do, the cautious thing to do is rinsing with milk.)
Here's what I've discovered — kefir grains are a lot more hardy than some people will have you believe, but at the same time, they absolutely react to their environment. Kefir will ferment more quickly in hot weather, and leaving it out in boiling hot weather will quickly cause it to over-ferment. That means your kefir is going to taste bad. It will ferment much more slowly in cold weather, to the point that it can basically just be milk after 24 hours. In that case, you'll want to do as another friend in a colder climate did, and get yourself a reptile heating pad to encourage fermentation. The amount of milk you add will affect the fermentation time, of course. The kind of milk you use does influence the taste, but you can actually both full-fat an skim milk. (The only milk you probably shouldn't try is powdered.)
After some time, you will learn exactly what your kefir grains need — and they "guide" you with the taste of the final product. (If it comes out too sour, stick it in the fridge for a "second fermentation" for about five hours.)
Here's another thing: your kefir grains will gain between five and seven percent in mass every 24 hours , so if you start off with one jar, you'll soon have two. Not only does this signal you can share with others, it also means you can afford to experiment with one jar a bit without risking losing your little operation.
The Bottom Line
Making kefir at home with kefir grains gives you a pleasant and healthy drink, and it's fun too. Get to know your kefir and meet its needs, and it will serve you well. Good luck, and don't forget to enjoy the process!