Many people assume that because yogurt and milk kefir are both cultured dairy products, there aren't many differences between the two. This is actually not true. There are several differences between yogurt and milk kefir, including how each is made, the types of bacteria present in each, and the flavor and consistency. If you understand the differences between yogurt and milk kefir, you'll be able to decide which of these cultured dairy products is right for you!
There are two types of yogurt starters: mesophilic and thermophilic.
mesophilic means that the yogurt starter is cultured at room temperature.
thermophilic means the yogurt starter is heat-loving. This type of yogurt starter is best prepared in a yogurt maker or similar appliance and it will culture at around 110ºF.
Milk Kefir is a mesophilic culture, which means it cultures at room temperature.
Yogurt starters come in both reusable and single-use varieties. Reusable yogurt starters, once activated, are re-cultured by mixing a bit of a previous yogurt batch into fresh milk. Once the new batch is complete it becomes the starter for the next batch, and so on. Yogurt cultures generally require re-culturing at least once a week.
Direct-set, or single-use, yogurt starters come in powdered form, and are usually thermophilic. Each new batch of yogurt requires a new packet of starter cultures. While this type of yogurt may be re-cultured a few times, at some point a new packet of powdered starter will be required.
Similar to culturing yogurt, milk kefir can be cultured using a reusable or single-use culture.
While a bit of the previous batch of yogurt is used for culturing yogurt continuously, milk kefir, on the other hand, is cultured continuously using milk kefir grains. The "grains" are actually a gelatinous mass harboring a generous variety of bacteria and yeast from which one can make continual batches of kefir. Milk kefir grains need to be transferred to a fresh batch of milk about every 24 hours.
Milk kefir can also be made from a powdered kefir starter, similar to a direct-set yogurt culture. Powdered kefir starter culture may be re-cultured a few times using kefir from the previous batch, but eventually, new powdered starter will be required.
Types of Bacteria Present in Kefir vs. Yogurt
Yogurt and milk kefir contain different types of bacteria, each of which performs different tasks.
The beneficial bacteria found in yogurt help keep the digestive tract clean and provide food for the friendly bacteria found in a healthy gut. They pass through the digestive tract and are called transient bacteria.
The bacteria in milk kefir, on the other hand, can actually colonize the intestinal tract. Kefir also contains a far larger range of bacteria, in addition to containing yeasts.
Yogurt generally has a flavor familiar to most people. Different varieties of yogurt starter produce yogurt that varies from mild to tangy. The consistency of yogurt varies from a thin, pourable yogurt, such as Piima, to a fairly thick, creamy yogurt such as Bulgarian. Most varieties of yogurt are thicker than kefir, though.
Milk Kefir is also tart, but it can have a touch of yeast flavor, due to the beneficial yeasts present in the culture. Milk kefir's flavor is more sour than yogurt's flavor, and has been described as a cross between cultured buttermilk and yogurt. While yogurt is almost always eaten with a spoon, milk kefir is usually consumed as a cultured dairy drink.
Versatility of Kefir & Yogurt
Milk kefir can be drained of whey to make a spoonable kefir, soft spreadable cheese, kefir cream cheese, or even hard cheese.
In addition to these different cheese products, both yogurt and milk kefir are quite versatile, and can be used in many recipes, from dips to baked goods.
Conclusion: The Choice is Yours!
In short, yogurt is a good source of probiotic bacteria, that requires weekly maintenance, depending on the culture chosen. It is generally a spoonable consistency and may be mild or tart in flavor. Yogurt may be used in a variety of recipes.
Similarly, milk kefir is also a great source of probiotic bacteria and yeast. If using milk kefir grains, you'll need to make time for daily maintenance to make milk kefir. It is also generally more sour in flavor and of a pourable consistency. There are countless milk kefir recipes.
Despite which cultured dairy product you decide to make, both yogurt and milk kefir offer probiotic benefits and, with our starter cultures, allow you to make real food, right at home. Choose the cultured dairy that is right for your lifestyle and don't hesitate to reach out with any questions. We're here to help!