How to Make Soy Milk Kefir

soy milk kefirHow much do you spend on those little snack containers of soy yogurt/probiotic every month?

Why not pay a small fraction of that amount for a far superior probiotic food? In today’s blog post, you will find 2 simple and clever ways to make your own soy milk kefir. The first method will contain trace amounts of dairy, and the second method is 100% vegan.

Before we move onto the steps and instructions, I’d like to step back and address a few things that might help you be more successful in making your own soy milk kefir.

What is milk kefir?

Milk kefir is a probiotic drink that contains a variety of beneficial bacteria such as lactobacillus acidophilus, bifidobacterium bifidum, et al, and strains of yeast. It is made with either milk kefir grains or a kefir starter culture.

I personally like the hydrated kefir grains method because the grains can be reused and will multiply over time. I have read that milk kefir made from kefir grains contains significantly more bacteria and yeast than that made from the kefir starter (see link here).

Live milk kefir grains are a combination of micro-organisms, such as lactic acid bacteria and yeast in a matrix of proteins, lipids, and sugars that looks like cauliflower. During the fermentation process, kefir grains consume the lactose present in milk and break it down to lactic acid, ethanol, carbon dioxide, and other substances that contribute to the unique flavor of milk kefir. The fermentation process also breaks down the dairy protein into amino acids, which is believed to be easier to digest.

In short, milk kefir grains will continue to grow when they consume lactose, the sugar found mainly in mammals’ milk. People who have lactose intolerance will find milk kefir to be a great dairy, lactose free probiotic drink that they can make at home.

However, for those of you who want to reduce your intake of animal protein, here are 2 ways to make a vegetarian/vegan plant based protein probiotic drink

Method 1. Use (Dairy) Milk Kefir Grains

soy milk kefir

After straining the milk kefir to remove the kefir grains, I gently rinse the milk kefir grains with filtered water (chlorine in tap water is not friendly to kefir grains). Place the rinsed milk kefir grains in a glass jar and pour in some sweetened soy milk. I leave the jar on the kitchen counter for approximately 18-24 hours to let the soy milk ferment. When it thickens and has a moderately sour taste, it is ready to be strained. At this point, if you gently shake the jar, you should see a delta rivers type of coating on the wall of the glass jar.

soy milk kefir

a delta rivers type of coating on the wall of the glass jar

I use the Silk Original soy milk, and it works great. I haven’t tested other brands, but I believe other brands will work too. Be sure to use the sweetened ones because the kefir grains need to consume sugar to survive. After one or two batches, I switch the kefir grains back to dairy milk to revitalize the grains.

Because the milk kefir grains may contain some dairy milk, this method is not guaranteed to be 100% dairy-free.

Method 2. Use Water Kefir (Grain Free Method and 100% Vegan)

soy milk kefir

I don’t mean to brag, but this is a method I came up with myself. You don’t use any kefir grain, so no straining after fermentation is needed! It is vegan soy milk kefir.   I found that someone else had made their own cultured coconut kefir milk at home using water kefir. Yes, the water kefir, the ready-to-drink water kefir but not the water kefir grain. So I decided to try the method out on soy milk. It works! Cheers!

Using my chemistry background I performed a controlled experiment on growing this soy kefir as follows: I mixed ¼ cup water kefir with 2 cups sweetened soy milk in a glass jar. I left this on the kitchen counter and let it ferment for 24 hours. For the control group, I simultaneously set out another jar of 2 cups soy milk, without any water kefir, to compare. This will ensure that the formation of soy curd at the end of fermentation is from the real fermentation process but not the soy milk going bad as a result from sitting out at room temperature for so long.

Here is the fantastic result.

After 24 hours of fermentation, soy milk in the jar with water kefir became slightly thicker and has a hint of sour taste. This is the best time to enjoy the soy milk kefir as a beverage. It will continue to ferment even after being refrigerated. Eventually all the soy curd will be floating on top with the liquid (soy whey and water) on the bottom. I found it’s hard to stir it up into a homogenous beverage at this point, but you can carefully scoop out the top without any liquid and use it as soy cream cheese. Did I say this is a genius idea?

As for the control specimen (soy milk without any water kefir), nothing happened. It didn’t go bad. It tasted the same at the time when I first set it out as it did at the end of the 24 hours.

Now you have two convenient and economical ways to make your own soy milk kefir at home. Do any of you have any other ways to do it such as different methods or growing it from different cultures? I’m always interested in hearing about different things others have tried.

soy milk kefir

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How to Make Soy Milk Kefir
Tools: Quart ball jars with storage lids, rubber spatula, a large bowl, measuring cups, stainless steel mesh strainer.
  • Milk Kefir Grains Method
  • 1 tbs hydrated milk kefir grains
  • 2 cups sweetened soy milk (Silk Original Soy Milk)
  • Water Kefir Method
  • ¼ cup water kefir
  • 2 cups sweetened soy milk (Silk Original Soy Milk)
Milk Kefir Grains Method
  1. Place hydrated milk kefir grains in a glass jar, then add soy milk. After a gentle stirring, cover the jar with plastic lid, paper filter, or cheesecloth and keep the jar at room temperature (between 72-78 °F) to ferment for 24 hours. At some point, you will see some clear liquid (soy kefir whey) showing at the bottom of the jar with thickened curd floating on top. Gently stir to mix the floating curd back in the whey and let it continue to ferment until the soy kefir achieves a moderate sour taste. If the jar is kept at room temperature for a longer period of time, the soy milk kefir will be more tangy due to the longer fermentation process which produces more acid.
  2. After this time, the soy milk kefir is ready to be filtered. Place the mesh type strainer over a large bowl. Use spatula gently working the kefir through the strainer. Save the kefir grains and repeat step 1 for the next batch of soy milk kefir. If the fermentation was too long, and a large amount of kefir whey was formed, use spatula to stir gently before this straining step.
  3. After a few batches, transfer the kefir grains back to dairy milk to revitalize.
Water Kefir Method
  1. Place water kefir and soy milk in a clean glass jar. Cover with lid and keep the jar at room temperature (between 72-78 °F) to ferment for 24 hours. Serve as it is.
  2. The leftover soy milk kefir can be refrigerated. However, it will continue to ferment even at low temperature. Separation of soy curd from the liquid soy whey is normal. The soy curd on top can be scooped out and used as soy cream



  1. Rhoda says:

    Hi, I was googling soy milk kefir today and found your blog! This summer I added my milk kefir grains to soy milk and left it in the fridge so it would slowly ferment. I think there was 1 or 2 cups of regular milk in the jar when I did this.
    Today I noticed that the kefir had separated so I shook it up.
    I took the grains out and began pouring the kefir through a coffee filter and it appears to be straining just like regular milk kefir.
    I sure hope that it makes yogurt cheese! I haven’t heard of anyone trying it so I was glad to find your blog today!

    • Joyce says:

      The milk kefir grain method works pretty well. I haven’t try to make cheese. I’m thinking if you make your soy milk really concentrate or maybe add cornstarch to thicken it before the fermentation step. This may give you a thicker, yogurt-like result. Anyway, let me know how your yogurt cheese turns out! 🙂

  2. Alina says:

    Hi Joyce,
    What is the maximum number of batches of soy milk I can make from one set of milk kefir grains?
    Once I put them in regular milk then will just one batch be enough to revitalize the grains?
    Thank you.

    • Joyce says:

      I’d say for each 2 batches of soy milk kefir, you should put the grain back to the dairy milk to revitalize. Otherwise, the grain won’t be very “healthy” and effective for more batches of soy milk kefir.

  3. deborah says:

    I’m anxious to try the kefir with the water grains. Been making milk kefir a couple years & read a book that said pasteurized milk contains blood, pus & animal focus. I haven’t been able to make it since. Do you think the kefir grains will eat that horrible stuff from the milk? Thanks.

    • Joyce says:

      Wow, I haven’t heard this before so I really can’t answer your question. It sounds interesting so I’ll definitely look it up. Thanks for sharing this information.

  4. murl says:

    I’ve been making soya milk kefir for the past week. I just used a small amount of milk kefir as a starter and do like this each day. Just leaving a small amount of left over kefir to start the new batch.
    Been working well so far

  5. Clifford says:

    I am inspired to try this recipe and was led here after reading about the benefits of sour milk by an extraordinary man by the name of Gurdjieff. I will return with a report on the results. Thank you.

  6. Jake says:

    Have you tried/do you think that this method would work with other milk substitutes? I was thinking of using rice milk since I’m allergic to soy.

    • Joyce says:

      I haven’t tried using this method for rice milk. However, I did grew rice milk probiotic by combining sugar, rice milk, and probiotic powder together and let them stand at room temperature. If you are interested, try it. Or if you’re interested, you can search my post titled “how to make fermented sweet rice” Let me know if you have any further questions.

  7. Helen Yow says:

    Hi Joyce, Thank you for your great post. I have been doing soy kefir for only three times, but I used non-sweetened soy milk. So my poor grains must be starving by now.

    I did add milk though. I have tried one part milk one part soy. I have also tried one part milk three parts soy. Is that alright? Do I still need add sugar for the grains? If yes, what kind of sugar? I have some maple syrup. Would it be a great waste to add if the grains consume sugar indiscriminately?

    Thank you very much.

    • Joyce says:

      If you use milk, I think it’s not necessary to add sugar. You could add granulate sugar if you’d like to. I never tried maple syrup but I do know honey will not work and will “kill” the grains.

  8. Kimberley says:

    I always make my kefir milk with 1/2 skim milk & 1/2 soy milk. The grains seem to survive & multiply and the end result is always great for my berry & banana smoothies.

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