Sofia Eydelman is a holistic nutritionist and food blogger, sharing stories and recipes on her blog - From the Land We Live On. Her current interests include intuitive cooking, urban gardening, traditional food preservation, learning about wild food, and exploring the ways that all of those things come together to cultivate personal balance and a healthier food system. She believes that green food comes in every color, and that learning how to celebrate abundance is an important step towards sustaining our health.
Milk kefir is a fermented dairy beverage, traditionally made by using kefir “grains” to culture ruminant milk. These grains are not related to actual grains at all, but are a symbiotic culture of bacteria and yeast (SCOBY), a unique and diverse group of microorganisms bound by lipids, proteins, and carbohydrates. (This is similar to, but slightly different from, the SCOBY that is used to make kombucha.) Milk kefir is valued for its delicious, tangy, creamy taste and effervescent qualities, as well as a number of reported health benefits due to exceptional probiotic diversity and potency.
What’s really fascinating and mysterious about kefir grains is that no one really knows exactly how they came to be, or is able to create them from scratch. The grains that are in circulation today have been passed down, from their origin, for many generations. It is widely speculated that kefir originated in the Caucasus Mountain region as a way to preserve milk. It has since become popular in many parts of the world, and recently North America.
Different Ways of Making Milk Kefir
Today, kefir can also made by using a freeze-dried starter culture, a powder containing a subset of the bacteria and yeast common to kefir grains. It can also be made by inoculating milk with some store-bought kefir, a process that will highly depend on the probiotic quality of the initial product.
All of these methods work to make a delicious, fermented beverage, but using grains is the best way to ensure maximum variety in the microorganisms that are present and have been traditionally used to make kefir. The grains adapt to their environment and evolve over time, so there’s high variability in the range of microorganisms found in any given batch. While there are some common strains that have been used to produce the starter cultures, it's hard to mimic the true spectrum, so many will argue that the only way to make true kefir is to use the grains.
Regardless of the chosen method, kefir is the easiest fermented dairy product to make at home, as the fermentation works best at ambient room temperature. Grains will multiply over time and can be used indefinitely. Starters and cultures, however, have a limited lifespan and new ones will have to be acquired to continue the process.
While kefir is commonly made with cow's milk, especially in North America, any ruminant milk (e.g., goat, sheep) can be used. It can be made with either raw or pasteurized milk. The fat content of the milk, while may impact the final quality, should not have significant effect on fermentation. Lactose-free milk, however, may not work as well, given that some of the bacteria and yeasts in the grains rely on lactose for fermentation.
What's the Difference Between Milk Kefir and Yogurt?
Like yogurt, kefir grains contain various bacteria species in the lactobacillus genus. These bacteria ferment lactose into lactic acid, resulting in a delicious, tangy drink. The yeast species in the grains contribute to kefir's unique effervescent (bubbly) quality by producing carbon dioxide during fermentation, a quality not found in yogurt.
Overall the diversity of microorganisms in kefir is much larger than in yogurt, which typically contains only a couple of species of bacteria, and does not contain yeast. The taste of kefir is pleasant and complex, and the consistency is thinner than yogurt, better resembling buttermilk or drinkable yogurt. Kefir can range in acidity and effervescence depending on the specific organisms present in the grains and the conditions in which it is made.
Milk Kefir in the Kitchen
Kefir is delicious plain, but is also commonly flavored and sweetened. Besides drinking it straight up, or with a few drops of maple syrup (delicious!), you can use kefir as a base for smoothies, baked goods, pancakes, and salad dressings. The commonly present yeast, Candida humilis, allows kefir to also be used as a starter for sourdough bread. There are many ways that you can get creative with kefir. Many recipes are available for chilled soup, kefir cheese, and even ice cream!
Water Kefir Is Not the Same
Milk kefir is not to be confused with water kefir, which is also made using kefir grains, but of a different composition and origin. Water kefir grains are used to ferment sweetened water and while there is some overlap with milk kefir with respect to the microorganisms, the grains are not interchangeable. As dairy-free diets are becoming more popular, many people are venturing out to make coconut and nut milk kefir—products ever-so-slightly resembling milk kefir. These products are usually made with water kefir grains, or a different culture. These products are starting to be produced commercially, like milk kefir, but should not be confused with true milk kefir, as they do not share all of the same properties.
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