Making Milk Kefir: temperature & how to choose a culturing period


Once you have successfully rehydrated your kefir grains you can get started on producing milk kefir every day in your home kitchen.

Milk kefir is a mesophilic culture, meaning it does not require the warmer temperature range, 100-115 degrees, that many yogurt cultures require. That said, temperature is a consideration in kefir-making.

The other big consideration is just how long you should allow your kefir to culture. You can achieve different flavors and viscosity depending on how long you allow it to culture. We’ll get to that in a moment, but first lets talk temperature.

A temperature of 65 – 85 degrees is ideal for must cultures, including kefir. Wild temperature swings should be avoided, so if temperature control is an issue in your home then you may want to consider insulating your culturing vessel with a towel or by some other means.

When we were first beginning to consume kefir I wanted to slowly ease us into it. In talking with a friend who had been making kefir for some time she recommended a 12 hour culturing period. Those 12 hours produced a thin, mild-flavored kefir.


As we have grown to love kefir, I have continued to increase the duration of the culturing period for a few reasons. A longer culturing period:

  • Produces a thicker kefir, more akin to yogurt.
  • Produces a nearly lactose-free kefir for those who need it.
  • Produces a larger number of beneficial bacteria.
  • Gives me a day to not have to think about it :).

That said, do consider the kefir grains when you are choosing how long to culture yours. I generally only culture mine for 24 hours simply so that the kefir grains do not run out of food.

If you’re just introducing kefir to skeptics, however, I would recommend the shorter culturing time which will produce a thin drinkable kefir great for smoothies.

Next time we’ll discuss growing more kefir grains!

What is your preferred warm location & culturing time for milk kefir?


Shannon is a mama to four small children, homesteader, freelance writer, and picture-taker. She lives with her husband on their off-grid homestead where they make and eat kefir, kombucha, sourdough, and fermented vegetables.

More Posts - Website

Milk Kefir vs. Water Kefir
Did you know there are two types of Kefir?  Both are delicious probiotic-rich beverages but there are a few differences including a dairy-free option.

See more Expert Advice Articles...


Milk Kefir FAQ
Read about common questions people have about making and using kefir.

See more Expert Advice Articles...


  1. Jacqueline says

    I often leave my kefir for 36 – 48 hours to culture.
    Sometimes if I do a 24 hour culture, I’ll add some lemon rind and allow for a second fermentation for 24 more hours.
    I want all the probiotics I can safely get.

    Has anyone done their kefir with raw goats milk? I’m venturing on that next week.

    • says

      Jacqueline – Neat! Yes, the 2nd fermentation is something we will be exploring down the road in this series. Thank you for sharing your experiences.

      Yes, I have made kefir with raw goats milk. I find the culturing process much the same and the flavor only slightly different.

  2. Jennifer says

    I have managed to kill my milk kefir grains once already. I did culture kefir successfully for a few weeks and then something happened and it just wasn’t working anymore. Because my home is pretty cool year round I put my kefir in the oven with the light on. I do have a thermometer so I make sure it’s not going above 85 degrees. I just have to be careful to remember the jar is in the oven before I turn it on to bake! I did purchase new grains and am looking forward to having kefir again. I really did ‘feel good’ when I was drinking it before.

    My raw milk tended to form a pretty hard layer of dried out cream on the top of the jar as I usually cultured for 24-48 hours. I just used a quart canning jar with a coffee filter over the top. The grains would then become mixed in with the hard cream and I think I tried scraping them too hard through the sieve and that may be what killed them. Any suggestions of how to work that out well?

    • michael says

      a couple suggestions; if you have a light shining on the jar, try covering up the sides with a cloth to keep the mixture in a low light situation. if you are using milk that is not homogenized, then you will get separation of cream & whey naturally. if it is homogenized (store bought), then try giving the mix a shake every couple of hours (this is actually beneficial for the ferment). Another thing would be to shorten the ferment time, or use less kefir grains per batch. depending on how close the light is to the jar, it may be drying out the top layer. As well there is not much air flow taking place if the oven door is kept closed. I ferment my kefir at 68-70f during the winter with no problems other than it taking a bit longer. possibly try moving the jar to the warmest room where you live and see if you get different results.

      • Zsofia says

        They multiply just not quickly. I love eating the kefir grains the best, really.
        I haven’t noticed any ill effects from leaving it. Since I live in the Northeast our temps are cooler. My kitchen stays cool except when the oven or crock pot is going.

  3. Lindsey says

    This was helpful. I fail at my kefir over and over, and I can’t seem to find the right equation. It is lumpy and separated, and time/grain ratio hasn’t seemed to change it.

    I’ve been wondering if my routine is the problem. I’ve been making it once a week and putting the grains in the fridge for the other 6 days covered in an inch of milk. Could this be the problem?

    Thanks for any help!

  4. says

    Thanks, Shannon! I read your personal blog and just read your first post over here. I’ve been reluctant to start my kefir grains because a few days ago I ruined my CFH yogurt master starter. I can try again, of course, but I didn’t want to waste anything else! Silly logic, since its not doing us any good in the box!! I’m going to start rehydrating my grains tonight! Can you strain kefir to make a yogurt like product?

  5. Caroline Szymeczek says

    While 24 hours worked well for me for a while, something changed (likely there were too many grains as Shannon suggests!). So I tried to make sure that I had a constant amount of grains, and since I had a balance on my counter, I weighed them :). I arbitrarily decided on 6 grams of grains for a quart. That worked for a while…and I ate my extra grams every night. Turns out my grains grew by about 2 grams/day so I had a eat a couple of grams every night. Then it got warm, and my kefir just didn’t like it. Now I am culturing the 6 grams in a quart of milk at room temp for 24 hours but THEN continuing the culture in the fridge for another 24 hours. This is making PERFECT kefir! After the first 24 hours, the kefir is just starting to separate at the bottom a little bit, and its creamy in places. After the second 24 hours in the fridge, it is really like custard but it is not overly tangy, such as what I got with a “secondary ferment” when I removed the grains and left it at room temp for the extra 24 hours….

    • Jennifer says

      Caroline, when you do the second ferment in the fridge, do you leave the grains in or take them out first?

    • says

      Caroline – That’s so interesting! I love reading about how others are doing it and finding success. It seems like we can all pick up little ideas from others experiences. Thank you for sharing!

  6. Myra Horst says

    I am new to using kefir grains. I’m a little puzzled about how to get the grains out of the kefir. Are they scraped off the top? Or do I put the whole batch of kefir through the strainer into another jar. I thought the kefir would get thick, and this would make it difficult to get through the strainer. There’s probably a very simple and practical way to do this, but I’m missing it. Somebody help!

  7. says

    I learned about Kefir from our daughter about five months ago and we both have been making milk kefir every day. I use non gmo whole milk from Central dairy, located in Missouri. My grains are thriving on the whole milk and growing like crazy! I brew a quart every 14 to 24 hours, depending on the time I have to tend it. I drink a tall glass about three times a day. I am 70 years old, in good health, and still work a full time job in Labor and Delivery at our local hospital. I brew my kefir with about 10 average size grains in the quart jar filled 2/3 full of milk with a coffee filter on top. It has its own dark cupboard and stays an even 72 degrees.
    I rotate the grains with the excess kept in the refrigerator covered with milk. I strain off the refrigerated grains once a week, add that milk to the available kefir to drink, rinse the grains with distilled water, and cover them with fresh whole milk. If my quart jar of kefir separates into whey and kefir, I just stir it up good and strain it off as usual. I add about a half cup of flavored creamer to each quart of drinkable kefir in the refrigerator. Kefir is a blessing, and I am thankful to have it.

    • says

      Toni – Thanks so much for sharing your kefir testimonial! It sounds like you are doing a great job caring for your grains and utilizing this amazing beverage. We appreciate you stopping by and are glad to hear from happy fermenters such as yourself!


Leave a Reply

Your email address will not be published. Required fields are marked *