MAKING MILK KEFIR
GETTING STARTED WITH MILK KEFIR
Milk kefir is a sour, drinking yogurt, and it was the first ferment I rabidly consumed that actually solved a particular body issue for me. The first thing to know about milk kefir is that you need a culture to make it (the kefir grains pictured above) and that getting a culture is well worth it, even if you have to buy it, although I do recommend searching hippy listserves, craigslist and other sites for people willing to part with their grain babies before you buy.
ABOUT MILK KEFIR GRAINS
Although they’re usually called grains, these little guys are actually SCOBYs or symbiotic communities of bacteria and yeast, so for those of you who avoid grains, no worries! Their name most likely stems from their “grainy” appearance (although wouldn’t “kefir cauliflowers” have been more appropriate?) so go forth and kefir all ye Primals. These particular cultures are extremely rich in probiotic bacteria and yeast. The most complete list of kefir grain microbes (both yeast and bacteria) that I’m aware of is located on Dom’s Kefir in-site. It is quite a long and well-sourced list. The “food” of milk kefir grains is lactose or the sugars that naturally occur in milk. The kefir culture transforms these dairy sugars into a few different things, including lactic acid, CO2 and small amounts of alcohol. They also synthesize plenty of interesting enzymes and compounds during the fermentation process. I highly recommend poking around on Dom’s site, linked above, if you’re interested in microbial information and links to studies that have been performed to date.
HOW TO CREATE THE RIGHT SELECTIVE ENVIRONMENT FOR MILK KEFIR
The essential elements for successful milk kefir fermentation:
- Temperature – Room temperature is great for milk kefir. I have found that anything in the 64 to 78 degree F (17.7-25.5 C) range will work just fine. In my experience, a broad range of “room” temperatures work well for kefir, but major changes in temperature will impact the speed at which your kefir ferments. When the seasons change, your kefir will most likely need a little adjustment time. Warmer temperatures will speed up fermentation, lower temperatures will slow it. I find that in periods of seasonal change, my kefir is sometimes thin in consistency or very yeasty smelling. I don’t let this bother me too much, as they always come out fine after a week or two of adjustment.
- Aerobic or Anaerobic? – There are different kinds of fermentation. Some require air, others require no air. Milk kefir is technically an anaerobic process, but you don’t need to work to keep your grains submerged like you do when pickling vegetables. The milk itself seems to be a sufficient barrier to air, and many of your grains will stay at the bottom of your vessel during fermentation.
- Fermentation Time – There is definitely some subjectivity here, although you do want to care for your grains by giving them a somewhat balanced living environment. The longer they ferment the more acidic your kefir will be and the lower it will be in lactose. I don’t recommend fermenting for longer than 48 hours. Although these grains are acid tolerant, even they have their limits. If you like a lower lactose product, I recommend continuing fermentation (secondary fermentation) after removing the grains. If you want to experiment with longer fermentation times, you can always wait until your grains grow enough to split and then use your spare set for experimentation. My preferred time is 24 hours during stable periods. When the weather gets very cold, they usually need at least 36 hours. When the weather gets very hot, they are occasionally done in 12 hours.
You can make milk kefir from just about any kind of milk, but please read below exceptions and details. Just remember to give your grains a period of adjustment when you switch from one milk to another.
- Fat content – Every set of grains I’ve had has been happiest in full-fat milk. The texture and consistency are more to my liking and the grains seem to ferment and reproduce more readily in full-fat milk than in lower-fat milks. However, lower-fat milks are totally fine to use if that’s what you and your family prefer. Your grains may reproduce more slowly, and your final product may not be as delicious, but that’s okay (and also subjective!)
- Raw vs. Pasteurized – Some grains that you purchase will come with a note or a warning that raw milk can kill them. Raw milk has a very heavy bacterial load that can sometimes compete with or dominate the colonies in your grains. I have had this experience. When you get new grains, I recommend growing them in the same type of milk that they have been grown in by their previous owner, at least for a while. If they’re used to pasteurized and you want to use raw, give them a couple weeks in their original milk, then split the grains. Run them through the normal kefir paces for a couple weeks and see how they’re doing, and continue to maintain a batch in the pasteurized milk, just in case. After several batches, take note: Have your grains shrunk or grown (weighing them before you start is a good way to measure this? Is the kefir you’re getting ideal in flavor taste and texture? If they seem to be thriving after several batches, you are good to go.
- Animal – Goat milk kefir is delicious. I’ve never had sheep’s milk kefir but word around town is that it, too, contains lactose, the food of the kefir grains, and so should work well. Cow’s milk works great.
- Non-Dairy – Non-dairy milks do not contain lactose and are therefore inadvisable. You can do the tricky, dual-culture method, in which you switch your grains back to dairy milk every week to 10 days, but most people find that too difficult to maintain. If you are vegan or cannot have any dairy at all, I would recommend trying a different cultured beverage, such as water kefir or kombucha. If you dislike dairy or can only tolerate small amounts, you can use a very small amount of finished milk kefir to culture your non-dairy milks. Using 1 T of finished kefir to 1 quart of alternative milk usually does the trick. It’s not perfect, but it’s an option.
I can say that based on my own personal experience, kefir definitely has a special microbial community. It was the first ferment I consumed as medicine (although I truly enjoy the taste, as well) and it certainly did the trick!
MAKING MILK KEFIR
- Obtain grains.
- Place about 2 tablespoons of grains into a quart jar.
- Pour in your chosen milk. Fill to about the 3 cup mark.
- Place the lid on, or cover with a cloth and a rubber band.
- Let your jar sit at room temperature away from direct sunlight for 24 hours (see “Fermentation Time” above for more detail).
- Strain finished kefir into a jar through a nonmetallic, fine-mesh strainer.
- Place grains into a new jar or vessel and cover in milk.
If you are concerned about ingesting lactose, secondary fermentation is your friend. While all of the lactose won’t be gone, more of it will be converted than if you just stopped at primary fermentation. Secondary fermentation also increases the nutrient value of the kefir and it provides a great way to add in alternate flavors. I’ll often place a few pieces of fresh or frozen fruit, some ginger slices or herbs and spices into my kefir during secondary. It doesn’t provide an outrageous amount of the flavor of the thing you add, but it gives a subtle hint of what you added.
When kefir has been fermented for a while, it can begin to separate. It might not look pretty, but it is totally fine. The clear liquid is kefir whey, a magical substance that you can use to ferment other things that may not readily ferment (fruit chutneys, condiments, etc). If you want it to get back to a drinking consistency, simply stir it up using a non-metal implement. I use a chopstick.
If you can’t kefir every day for the rest of your life (who can, honestly?) grains can happily and safely be stored at in fresh milk in your refrigerator for 10 days. Even if you don’t culture your grains in whole milk, I recommend storing them that way. My grains always bounce back more quickly when they’ve been stored in full-fat milk.
RESOURCES FOR PURCHASING GRAINS
- Yemoos.com – I have never purchased milk kefir grains there, but I’ve been very happy with the water kefir grains I purchased there.
- GEM Cultures – I got my most recent grains there early last year after my old grains were killed in a horrible accident, and they’ve been absolutely great.
There are also those that sell cheaper grains (their grains’ babies) on Amazon, Craigslist, Ebay and Etsy. Always order from a source you trust, or better yet, get some freebies from your fermenting friends.
MILK KEFIR ON PHICKLE
- Dom’s Kefir Site
- Katz, Sandor Ellix. The Art of Fermentation
- Katz, Sandor Ellix. Wild Fermentation
- Christensen, Emma. True Brews