Have you ever found yourself standing in the aisle of your local supermarket, staring back and forth between kefir and yogurt, wondering which one to buy? You’re not alone. Most people don't understand the difference between these cultured dairy products. While kefir and yogurt have a lot of similarities, they're not the same. This post will clarify how yogurt and kefir differ from one another and leave you feeling confident about which one to buy on your next trip to the grocery store. Before we dive into the differences between kefir and yogurt, let’s clarify what they are.

What Are Kefir and Yogurt?

Kefir is a fermented beverage that contains beneficial yeasts, proteins, and probiotic bacteria (1). Like yogurt, kefir is frequently a milk product, but it doesn’t have to be. It all depends on how you make it. You can make kefir from cow’s milk, goat’s milk, sheep’s milk, coconut milk, rice milk, soy milk, or almond milk. Looking for a low-fat option? You can even make water kefir from coconut water. Yogurt is also a cultured product that may or may not be dairy based. You can make yogurt from the same dairy and non-dairy milk types listed above. Like kefir, yogurt contains beneficial yeasts, proteins, and probiotic bacteria, albeit in smaller quantities than are found in kefir (2). There are many different types of yogurts, from Greek yogurt, which is higher in protein, to reduced-fat or non-fat yogurt. You can also make kefir yogurt by using a small amount of kefir as the yogurt starter. According to Jane Chertoff of Healthline, “both kefir and yogurt are good sources of protein, calcium, potassium, phosphorous, vitamin A, as well as B vitamins like riboflavin, folate, biotin, and B12” (3). And for anyone who is lactose intolerant, kefir and yogurt are lower in lactose than other dairy products. That’s because the yeasts and bacteria in kefir and yogurt create lactase, which actually “consumes most of the lactose left after the culturing process” (4). Those who are still concerned about drinking dairy products can choose to make a completely lactose-free version of kefir or yogurt from non-dairy milk. Right now, kefir and yogurt might sound very similar to you. The main differences lie in their production, flavor, and bacterial makeup.

Kefir vs. Yogurt: Production Differences

Kefir and yogurt are made differently. You can make kefir using a starter grain (1). The starter grain doesn’t actually contain any grains — it’s just a clump of yeasts, proteins, and bacteria. It gets the name “grain” because of its clumpy appearance. It resembles tiny heads of cauliflower. The exact bacterial strains in each cluster of kefir grains differ grain by grain, but Lactobacillus is common in all grains (5). You can also make kefir using a kefir starter culture. This is a powder that contains many different types of beneficial bacteria. You can use it to make multiple batches of kefir, but it has a finite lifespan of about 2-7 batches. This is unlike kefir grains, which can technically make kefir forever (6). Powdered kefir starter also typically contains fewer strains of bacteria than starter grains do (6). Yogurt is made from a yogurt starter culture — there is no starter grain. You can get both reusable and single-use yogurt starter cultures. Reusable cultures are similar to kefir grains in that they can be used indefinitely to create multiple batches of yogurt. Simply use a small amount of your previous batch of yogurt to “start” your new batch — this is called re-culturing. Single-use yogurt starters are similar to kefir starter cultures in that they may be used a few times to create additional batches of yogurt, but the beneficial bacteria will ultimately run out. Ideally, you should use a new starter for each batch of yogurt when using single-use starters (7). Whether or not you use kefir grains or a kefir starter culture, kefir cultures at room temperature. This is unlike yogurt, which often cultures at a higher temperature. Most yogurt starter cultures are thermophilic — meaning they love the heat. However, you can get yogurt starters that culture at room temperature — these yogurt cultures are known as mesophilic (3). Kefir’s fermentation process is also longer than yogurt's. While kefir ferments for 14-18 hours (cold temperatures will increase this time further), yogurt only ferments for 2-4 hours (3).

Kefir vs. Yogurt: Flavor Differences

There is also a taste difference between kefir and yogurt. While both are tart, kefir is often described as more sour tasting than yogurt (7). A bigger difference lies in consistency. Kefir is thinner than yogurt, similar in consistency to a drinkable yogurt, and is often consumed as a drink. Yogurt is generally thicker and eaten with a spoon.

Kefir vs. Yogurt: Bacterial Differences

While both kefir and yogurt contain beneficial bacteria known as probiotics, kefir contains significantly more — about three times the amount found in yogurt (8). According to Leslie Beck of The Globe and Mail, “kefir is fermented with a mixture of 10 to 20 different types of probiotic bacteria and yeasts; most yogurts are made using only a few” (8). Moreover, the probiotics found in kefir are capable of colonizing the gastrointestinal tract, while those found in yogurt are transient bacteria — meaning they pass through the digestive tract (7). The greater the probiotic count, the greater the health benefits to your digestive and immune systems. Probiotics are proven to help the digestive system (9). In terms of digestive health, probiotics can help alleviate digestive problems like diarrhea and help treat irritable bowel syndrome, ulcerative colitis, Crohn’s disease, urinary tract infections, vaginal infections, and more (9). Probiotic consumption may even alleviate allergies and asthma, both of which are associated with the immune system (10). To get the highest amount of digestive benefits, support probiotics by taking prebiotics as well. Prebiotics help beneficial bacteria, including probiotics, survive and thrive by serving as food for the probiotics. There are some minor risks associated with kefir consumption. According to WebMD, drinking kefir could cause side effects, especially if you’re drinking it for the first time. These may include “bloating, nausea, intestinal cramping, and constipation” (11). These side effects are not reported for yogurt (12). If you have an autoimmune disease like Crohn’s disease, Hashimoto’s disease, or rheumatoid arthritis, or if you have a weakened immune system, we recommend you consult your healthcare provider before trying kefir or yogurt. Both kefir and yogurt boosts the immune system, so they could exacerbate autoimmune conditions (11, 12). Medications that suppress the immune system are contraindicated with kefir and yogurt, so they shouldn't be taken together (11, 12).

So, Should You Eat Kefir or Yogurt?

Bottom line: The choice between kefir and yogurt is ultimately up to you. Since both have health benefits, the best choice is ultimately the one you're willing to eat regularly. Both are cultured dairy products with non-dairy options, and the main differences between kefir and yogurt lie in the way they’re made, the way they taste, and the benefits they convey through their probiotics. Kefir is cultured at room temperature, while yogurt is often cultured at a higher temperature. While both are tart, kefir is slightly more sour and is a thinner consistency than yogurt. Kefir has a significantly higher concentration of probiotics, conveying greater health benefits to both the digestive and immune systems. Beware of added sugars and artificial flavors, colors, and sweeteners when purchasing commercial kefir or yogurt. When possible, opt for natural versions or make your own. Kefir may cause minor gastrointestinal side effects, and those with autoimmune conditions and weakened immune systems shouldn't eat kefir or large amounts of yogurt. As a friendly reminder, we're not doctors and this information does not constitute medical advice. We recommend that you speak with your healthcare provider or a nutritionist before adding a new food like kefir or yogurt to your diet. If you're ready to take control of your overall health, sign up for our email list and receive exclusive health tips straight to your inbox.