Are Kefir Grains Alive?

Kefir grains seem to be a true miracle of nature. They are able to preserve and enhance the taste of milk while also growing and multiplying at the same time. But, what are they exactly made of, and are kefir grains actually alive?

Kefir grains are in fact live microorganisms. They are a symbiotic culture of bacteria and yeast that occur in nature. Over time, kefir grains will grow and multiply just like a live organism.

In this post, we’ll cover some of the mysteries surrounding kefir grains. We’ll look at their origins, how long they can live, and how to best keep them alive! Hint: if properly cared for kefir grains can live forever as they will just continue to multiply. Amazing, right?

Where do kefir grains come from?

While the exact origins of kefir grains remain a vague mystery it is fairly well-established that they were first used to preserve milk in the Northern Caucasus Region of the former Soviet Union.

Most likely the people of Armenia, Azerbaijan and Georgia (the country) first used kefir grains as a means to prevent milk from going bad. Since there were no fridges around back then milk spoiled easily without fermentation.

File:Soviet Caucasus map.svg
Northern Caucasus – Origin of Kefir

And as it turned out fermenting milk with kefir grains not only preserved the milk but also added some valuable nutrients such as B-Vitamins and several beneficial bacteria strains. So, let’s all thank the people of Armenia for their ingenuity!

Kefir grains are not man-made but occur in nature as a symbiotic culture of bacteria and yeast. Symbiotic because the bacteria and yeast live harmoniously side-by-side and work together in digesting simple sugars such as lactose.

How long do kefir grains live?

Kefir grains as a whole microorganism can essentially live forever. Of course, individual grains become weaker over time but as the entire symbiotic culture grows and multiplies new microorganisms form.

However, there are a couple of prerequisites for kefir grains to live that long. As a live organism they need the proper nutrition to grow and multiply as well as suitable environmental conditions.

Although kefir grains are fairly robust they tend to do best in temperatures ranges from 60-75°F (15-20°C) and with plenty of lactose or other sugars to consume.

How do you know if kefir grains are dead?

Even though kefir grains are resilient organisms they can eventually die off if conditions are not quite right. This can be caused by too little food or external factors such as excessive heat. Let’s look at some of the signs that your kefir grains might be dead:

  • Not floating to the top: One of the most telling factors that your grains might no longer be alive and working is that they will not float to the top of the milk after a few hours. When they remain at the bottom of the jar it usually means that carbon dioxide production is low and that no lactose is being digested.
  • No separation in kefir: Another way to test if kefir grains are alive is to let them sit in milk much longer than usual and to check if a separation occurs between the whey and the milk curds. Usually, this kind of separation will occur after 24-48 hours depending on your room temperature.
  • Kefir tastes like milk: When your kefir actually tastes just like milk you’ll know that your kefir grains are no longer working. A slightly sour taste and thicker texture should be present in well-fermented kefir.
kefir separation
Separated Kefir – A sign of healthy kefir grains

Before throwing your kefir grains out rinse and repeat multiple times. Sometimes your grains will just need some time to reboot and get back to work especially if they’ve been left in the cold for too long!

How many times can I use kefir grains?

Kefir grains can be used indefinitely if properly taken care of. Over time, as they digest more and more lactose and ferment your milk they will only grow stronger. However, maintaining good environmental conditions for your grains to thrive is key to extending their life span.

In the next section, I’ll go over some tips to make sure to keep your grains healthy and alive. The most important factor you’ll want to avoid to keep using your kefir grains indefinitely is excessive heat. But there are also some other factors to consider.

How to keep kefir grains alive

Keeping your grains alive can be as simple as maintaining steady room temperatures and providing plenty of milk. In fact, kefir grains don’t require much care at all just a consistent set of conditions.

Here are some of the most important things you can do to keep your kefir grains alive and well:

  • Food: Kefir grains require food like any other living organism. In the case of kefir grains that food is sugar. Water kefir grains feed on sucrose and dextrose while milk kefir grains digest the lactose in milk. Make sure to always keep your grains submerged in plenty of milk and never leave them sitting in the same liquid for too long.
  • Temperature: One of the most important things you can do to keep your grains alive is to shield them from high temperatures. Don’t set up your fermentation vessel near the heater or in direct sunlight. Obviously, cooking or frying kefir grains will also be detrimental to their life span.
  • Storage: Storing kefir grains when taking a break from making kefir is a delicate matter. The simplest way of doing so is to fill up a glass jar with plenty of milk and store your grains in the fridge until you continue the fermentation process. However, kefir grains will not survive indefinitely in the refrigerator. I’d recommend a maximum of two weeks before changing the milk.
  • Freezing: Kefir grains can technically be frozen but it might damage the microorganism in the long run. If kefir grains are frozen for too long the symbiotic culture might not make it. Once the balance of bacteria and yeast is upset your kefir quality will likely suffer. Preferably store in the fridge and freeze with care!


Kefir grains are robust cultures that occur in nature. These magical grains ferment and preserve milk and can last forever. All they ask in return is that you take care of them!

And caring for kefir grains is not that difficult: give them enough food on a regular basis and avoid extreme outside conditions and you should be able to use your kefir grains for as many times you like to make delicious and creamy kefir 🙂


  • Hi, I'm Marvin! In early 2019 I started fermenting sauerkraut, kefir, and kombucha and noticed the incredible health benefits that came with it. I was less irritated, had fewer allergies and my skin got better. I started this blog to share how fermented foods have helped me and how simple they are to prepare! Look around and see what speaks to you and all the best on your fermentation journey!

Leave a Comment