What Is the Difference between Yogurt and Kefir?
Many people assume that because yogurt and kefir are both cultured milk products, there isn’t much difference between the two. This is not true. There are many differences between yogurt and kefir, including how they are made, the type of bacteria present, and the health benefits of each.
There are two types of yogurt: mesophilic and thermophilic. Mesophilic means that it is cultured at room temperature. Thermophilic means that the culture requires a specific range of temperatures to incubate.
Kefir is a mesophilic culture which means it can culture at room temperature. Many yogurt strains, however, are thermophilic and require some sort of warming device to properly culture.
There is also a difference in what is used to propagate the culture in the milk. Yogurt is made by mixing a bit of a previous yogurt batch into fresh milk. Once the new batch is complete you may use that starter again, or in the case of raw milk a separate starter is kept with pasteurized milk. Yogurt can also be made with a dried starter.
Kefir, on the other hand, is made with either a dried starter or a set of kefir “grains.” These gelatinous grains will multiply over time, leaving you with extra grains to use, give away, or compost after every batch. In making kefir, the grains are simply removed from a newly made batch of kefir and added to fresh milk to make the next batch.
Types of Bacteria Present
Yogurt and kefir contain different types of bacteria, each of which perform 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 kefir, on the other hand, can actually colonize the intestinal tract. Kefir also contains a lot larger range of bacteria, as well as yeasts. So while yogurt may contain a handful of different strains of bacteria, kefir may contain many more than that.
Kefir Contains Yeasts
Both kefir and yogurt are lactic acid fermentations. On top of that, though, kefir contains beneficial yeasts that can also produce alcohol.
Texture and Flavor
Yogurt has a flavor that most of us are familiar with: tart, smooth, and creamy. Kefir is also tart, but it can have a touch of yeast or alcohol flavor to it due to the beneficial yeasts present in the culture.
Most varieties of yogurt are also thicker than kefir, given the same length of fermentation time. While yogurt is almost always eaten with a spoon, kefir can often be eaten with a straw out of a glass.
Both yogurt and kefir are beneficial cultured dairy products that can perform different, helpful tasks in the body.