Laura Killingbeck, a food systems consultant, has trained locals how to jar tart, seasonal vegetables and bottle live-culture sodas. This month, she showed off how simple it is to produce dairy treats at home.

Killingbeck’s three-part series on fermentation came to an end this month at Round the Bend Farm. Using the power of bacteria and yeast, all of her dairy recipes are packed with probiotics – microorganisms believed to enhance human health.

A portion of the class explored the history of milk and the dairy industry. She also addressed the merits of raw milk, a sometimes contentious topic. Some believe raw milk can be harmful to humans because it skips the pasteurization process. Others believe pasteurization kills off healthy bacteria.

Killingbeck said that, with pasteurization, “you’re killing off a lot of the life in milk.”

“It isn’t sterile. It still has bacteria, but it doesn’t have the same quantity of the important probiotic bacteria that are found in raw milk,” she said.

She said lactase is another enzyme killed off in the pasteurization process, and lactase is what helps humans digest lactose. She argues that because raw milk contains lactase, it’s easier for some to digest.

Nevertheless, when it came to the cooking portion of her class, Killingbeck said that either raw or pasteurized milk would work.

That’s because the key ingredient in Killingbeck’s recipes is dairy kefir, which has the consistency of a less viscous yogurt. The kefir is produced using a similar method to her medicinal sodas: adding a SCOBY (or a symbiotic colony of bacteria and yeast) to a solution and letting the solution ferment. Colony starter kits are available online.

She recommends one tablespoon of a bacteria and yeast mixture per liter of milk. The milk should be sealed in a glass jar and left to ferment for 24 to 48 hours at room temperature. She suggests shaking the jar slightly once a day.

“During that time period, the yeast and bacteria begin to consume the lactose – the milk sugars – and transformed them into lactic acid, carbon dioxide, a small amount of alcohol and some other organic acids,” said Killingbeck.

“There is some carbon dioxide production with this. It’s a slightly effervescent yogurt. It’s sometimes called the ‘champagne of yogurts,’” she said.

Once completed, the solution can be poured through a strainer to remove the kefir colony. The fermented milk, or dairy kefir, can be consumed as is or it can be mixed with honey or maple syrup. It can also be used as the base of a salad dressing or smoothie.

In her class, she demonstrated that bacteria and yeast can also be added to cream, which can then be processed into probiotic-packed butter, sour cream and buttermilk.

During the late summer and fall, Killingbeck helps the farmers of Round the Bend Farm process and ferment foods to keep the tenants stocked up for the winter. During the colder months, she heads to Costa Rica. She’s planning on heading south in early December.

“While I’m there I’ll be co-teaching an apprenticeship program. We’ll be doing workshops and classes on whole foods and fermentation for a group of eight apprentices as well as teaching some student groups that are there,” she said.

“That’s what’s so fun about going back and forth,” she added. “I focus on local, temperate foods here and local tropical foods in Costa Rica.”