Kefir grains are a cluster of bacteria and yeast mixed with protein and carbohydrates to form something that looks like cauliflower, for lack of a better comparison. If you have not seen kefir grains before, they are like nothing you have ever seen. They will appear strange and you will wonder why you should put them into perfectly good milk.
There are many reasons to add these foreign-looking objects to your milk. As you will read below, the milk is more easily digested and it may even be protective against cancer. Before gaining those great benefits, you have to figure out how to make it.
Kefir Grains: Just Dump Them In Your Milk
If you have made homemade yogurt, you know that you have to heat the milk to a certain temperature, perhaps let it cool as well depending on your process, and then add your culture.
Compared to yogurt, kefir is dead-simple. Use a clean jar, add the grains, and pour milk over them. The temperature of the milk does not matter (except that you would not want it too hot lest it kill the culture). It will come to room temperature as it sits. Cover the jar with a loose-fitting lid or a dish towel and let it sit for a day. You can let it sit longer or shorter depending on your grain to milk ratio and how sour you like your kefir.
(If you have purchased grains, you probably have about a tablespoon in which case you can add about a quart of milk and let it sit overnight or for about 24 hours.)
When your kefiring milk has sat for 12-24 hours (or more), strain the milk from the grains. If the grains are large, they will sit at the bottom of the jar. You can simply pour most of the milk off without pouring out the grains, and add more milk to the kefiring jar. This works well for a few days until it is time to clean the jar. In this case, set the milky grains aside and wash the jar.
You may use a strainer instead or one of those little cloth bags used in culturing. The best method is one that works for you with the equipment you can access.
Drink the kefir as-is or flavor it with fruit in a blended drink or smoothie.
At some point, you will get tired of making kefir. (Truly, this happens to the best of us.) You will wonder how to store your grains for the future.
Kefir Grain Long-Term Storage
Optimally, kefir grains are fed with milk (or sugar water for water grains) every day or two. When you go on vacation or simply get tired of the kefir regimen, it can be difficult to keep up with your kefir grains. You can put your kefir grains in the refrigerator and rejuvenate them later but depending on how long they were in the refrigerator and the conditions in your kitchen, they may never be the same. In our house, we have had success putting the grains in milk in the refrigerator for two weeks or so and ended up with good-tasting kefir after a couple of batches. What I do not know for sure is how much the microflora changed in that process, I just know that I end up with something that tastes like kefir.
Research tells us that the best way to preserve kefir for the longer-term, including all of its micro-flora, is to freeze it. A 1997 study in Lebensmittel-Wissenschaft und-Technologie found that grains stored at freezer temperatures (-20 and -80 Celsius) for 120 days (about four months) maintained their microflora. Those stored at refrigeration temperatures (4 degrees Celsius) produced kefir lower in acid and not as thick. The kefir was lower in quality, basically. The study did not follow the refrigerated kefir to determine if it could be “brought back,” though people have reported some luck with producing kefir from grains that have been in the refrigerator far too long. What you do may depend on if you have easy access to more kefir grains and how much milk you want to dedicate to the revival of the grains. We find here that it may take three or more bad batches before you begin to get a good-tasting product.
What I suggest is that when you have an abundance of kefir grains, freeze some for the future, just in case. This way, you will always have a stash.
Can You Make Kefir From Fluid Kefir?
In the case of yogurt, many people use the yogurt itself to make more yogurt, leveraging the microorganisms in the finished yogurt to inoculate a new batch. This is not possible with kefir because the balance of microorganisms in the kefir grains does not pass into the cultured milk in the same proportions. Some bacteria or yeasts in the grains may not even be found in the final kefired milk. Some strains live in the center of the grain and help keep the grain colony thriving, but do not add a great deal of microflora to the final product.
Milk Kefir Grains In Soy Milk?
Soy is a food best fermented to reduce phytic acid and other nutrient inhibitors. Inoculating soy milk with kefir grains is an extremely easy way to ferment soy milk. Some consumers find that the kefir grains do not grow and reproduce in soy milk. In fact, in some consumer kitchens, no kefir grains reproduce in any medium due to some unmeasured factor in the kitchen environment. Researchers have been able to get milk kefir grains to grow and reproduce in soy milk. As a result, it is worth a go in your kitchen if you are looking for a fermented soy milk option.
Culturing milk changes its properties and many people find milk kefir to be far more digestible than regular milk. Kefir originates from Eastern Europe and is extremely popular in Russia. It is common for every household to have a batch brewing. With a long history of kefir consumption and much common knowledge about digestibility, milk kefir has long been used in Russian and Soviet medical institutions to help people with impaired digestion.
Some people who are lactose intolerant find that they can tolerate milk kefir. One 2003 study found that participants with lactose intolerance had lower signs of gastric distress with a kefired milk. If you have extreme reactions to lactose, however, you may not want to engage in this particular experiment.
Kefir Grains: Anti-Tumor Effects?
One of the most intriguing areas of research on kefir is the purported anti-tumor properties. No human studies have been done on this issue but animal studies are intriguing.
In one study scientists isolated a component of the kefir grain and put it in the water of lab mice that they then injected with a carcinoma. For some mice, they gave the kefir grain-spiked water at the same time they injected cancer cells into them. In each case, tumor inhibition ranged from 40 to 59%.
Other studies have been done, none on humans, trying to determine which strains or components may actually be reducing the growth of tumors. The follow-up studies so far do not provide additional information to consumers than is provided by the 1982 study linked above. The bottom line appears to be that there may be some property in kefir grains that slows tumor growth. As with any area of limited research, there are no guarantees, but as consumers look for options to protect against cancer, kefir grains may be part of the picture.
The kefir grains themselves are different than the kefir they produce. The protective quality is likely in the kefir grain itself which leads to a key consumer recommendation: eat kefir grains. This sounds extremely nutty, but we allow some grains to slip into any blended kefir drink we may be making and the younger generation has yet to comment.