Kefir, the yogurt-like drink, is having a moment. From mainstream food magazines to an episode of "Diners, Drive-Ins and Dives," the fermented beverage seems to be everywhere.
People love it for its tangy taste and potential positive effect on the digestive tract. But not all kefir is created equal. Though commercially made versions of the drink are available at grocery stores all over the Baltimore area, enthusiasts insist that the best — and most beneficial — kefir is made at home.
Fortunately, kefir is easy to make. The process involves combining milk (or a nondairy alternative, such as coconut milk or sugar water) with kefir "grains"— a cluster of live cultures of yeast and lactic acid bacteria. The grains look like lumpy cauliflower or cottage cheese.
"I think it's one of the most underappreciated forms of fermentation, and one of the easiest. It's a very forgiving culture," says Meaghan Carpenter who, with her husband, Shane, owns Hex Ferments in Belvedere Square. The Carpenters make and sell a variety of fermented food, including sauerkraut, kombucha and kefir.
Though kefir and yogurt are similar, they differ in terms of taste, texture and fermentation process, says Gina Rieg, a Columbia-based health coach who teaches a class called "Homemade Probiotics: Crazy for Kefir and Kombucha."
"The taste is a little more sour than yogurt and it's not as thick," she says. Yogurt cultures at high temperatures, around 110 degrees, while kefir cultures at room temperature.
"It's similar to yogurt but the difference is that it is a mix of yeasts and bacteria; yogurt is just bacteria. Kefir, with yeast, has a fizzy feeling when you drink it," says Lina Brunton, who lives on a small farm in Millersville and has been making kefir at home for about two years.
She and her family use it in smoothies or mix it with fruit. It's also popular mixed with a bit of honey, maple syrup or cinnamon, or served with granola.
The Bruntons prefer using pasteurized milk for their kefir; Brunton says doing so makes it easier to ensure that the culture of the kefir grains "wins" over the cultures that exist in the milk.
Carpenter has a different perspective. "Raw milk makes delicious kefir, if you can get your hands on it," she says. But raw milk sales are not legal in Maryland. If you don't have a source of raw milk, Carpenter says "homogenized and pasteurized is fine. Skim is fine. But get good-quality milk."
Carpenter and Brunton agree that the milk should be as fresh as possible. "If it's been sitting in the refrigerator, it will grow its own colony of bacteria," says Carpenter.
Kefir is usually made with cow's milk, but it can also be made with water, coconut water and coconut milk. In her experience, water-based kefir is somewhat more effervescent than dairy kefir, says Brunton.
Even though kefir is a dairy product, placing it on the counter — not in the refrigerator — to ferment is perfectly safe, says Rieg. "The natural fermentation process will inhibit bad bacteria from forming," she says.
Kefir is a hardy culture, Carpenter says. "It can withstand extreme temperatures, can be frozen, dehydrated and rehydrated." She sometimes ferments her own kefir in the refrigerator; the lower temperature slows down the process of fermentation.
There are a few environmental considerations, however. "You don't want the jars in front of a window or vent," says Rieg.
The key health benefit of kefir comes from its large amount of probiotics — a broad term for the yeasts and bacteria that stimulate positive growth of microorganisms in the digestive tract.
"People use kefir for the benefits like calcium and protein but also for the probiotic functions — keeping the healthy gut bacteria," says Adina Fradkin, a registered dietitian in private practice with offices in Towson and Bel Air.
Fradkin says that there is not much existing research specifically focused on the health benefits of kefir. But still, she says, "Food is so important. You're not only getting the probiotic but also the other nutrients in the food. [With kefir] you're getting calcium, protein and maybe vitamin D."
As Rieg puts it: "The bacterial and beneficial yeast strains developed in kefir — dairy and nondairy — give our body more variety and strengthen the numbers of 'good guys' in our guts. ... We want the good guys to outnumber the bad guys."
People who are lactose-intolerant and cannot drink milk are still usually able to drink dairy-based kefir; the fermentation process minimizes the drink's lactose content.
The health of our digestive tract is linked to more than just whether we have stomachaches; sometimes seemingly unrelated symptoms can be alleviated by correcting problems in the gut. "Things like asthma and allergies and joint pain and even diabetes relate to our digestion," says Rieg. "You can have digestive distress and not 'show' it as a digestive complaint."
Homemade kefir contains a higher number of cultures and probiotics than store-bought, which is typically made with a starter culture powder instead of the grains. For example, the Lifeway brand of kefir is advertised as including 12 live and active cultures and 7 billion to 10 billion probiotic strains. Experts estimate homemade kefir could include up to 30 cultures and 40 billion strains of probiotics.
Though kefir has recently captured American hearts, stomachs and counter space, it is more than a passing trend. "It's thousands of years old and was developed by happenstance by nomadic herders in Central Asia," says Carpenter. "A lot of Central Asians are lactose-intolerant; it helped them use a food source that's available.
"They put the milk and grains in dried [sheep] stomachs and kept them on their horses or on the door frame of their yurts," she says. "It was your task, whenever you passed through the door, to hit the bag" in order to stir the kefir.
The tools might have changed, but otherwise, homemade kefir is pretty much the same as it was thousands of years ago.
Making dairy kefir at home
Making kefir at home is a somewhat inexact process; those who make kefir tinker with quantities and fermentation times until they find their ideal recipe and quantities.
Meaghan Carpenter of Hex Ferments regularly keeps one jar of ready-to-drink kefir on her counter at home and one jar slowly culturing in the refrigerator. The finished kefir can be stored at room temperature for one to two days, in the refrigerator for up to three weeks, and can be frozen for one or two months.
1 to 2 tablespoons kefir grains
1 to 4 cups fresh milk
The higher the proportion of grains, the faster the kefir will ferment, Carpenter says.
Place the grains in a clean glass jar. Pour the milk over the grains and either top with a (nonmetallic) lid or cover with a cloth or coffee filter secured by a rubber band.
Shake the mixture a few times a day. If the kefir is covered with a lid, occasionally open the lid to release any building pressure.
Let sit for 12 to 24 hours (and definitely no longer than 48 hours). "You'll notice the volume in the jar has risen," says Carpenter.
Pour through a sieve, into a bowl, or simply reach into the bowl, with clean hands or a spoon, and pull out the culture.
For more information, kefir lovers recommend checking out YouTube videos featuring Sandor Katz, author of "The Art of Fermentation." Katz describes himself as a "fermentation revivalist" and shares information about all different types of fermentation via his website wildfermentation.com.