Today I’m going to share with you how easy it is to make milk kefir at home. You’ll easily spend around $3 for a 32-ounce bottle of kefir at the store, but once you have your own starter grains, you can make kefir for the price of your milk. It’s a wonderful way to add a natural source of probiotics to your family’s diet.
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I love baking with sourdough and making various fermented vegetables, but kefir (pronounced kuh·feer) is the easiest fermented food we make in our home.
I’ve been making it for multiple years now after I received my starter culture from a friend.
There’s no heating or measuring temperatures like with yogurt making, and it’s ready to go in just 24 hours.
What is milk kefir?
Milk kefir is a fermented beverage similar to drinkable yogurt that is made using a starter culture called kefir grains. These grains aren’t made of grain at all, but are a bacteria and yeast culture that grows at room temperature.
They are squishy and cauliflower-shaped and are colored white or light-yellow. Fermenting milk with these grains will give you the cultured beverage known as kefir.
It’s tangy, creamy, and maybe even slightly fizzy. It has a different taste and smell than yogurt does.
Milk Kefir Benefits
Kefir is high in vitamins and minerals and is much lower in lactose than milk. Some people who are lactose intolerant can actually tolerate kefir as long as it has fermented long enough.
And as I mentioned before, it’s packed with probiotics, so it can help to balance the gut. It contains many more strains of bacteria and yeasts than yogurt does.
Some people with certain health conditions shouldn’t consume kefir, so it’s best to do your own research for your family.
*Stick with glass (not crystal), plastic, wood, or stainless steel utensils and containers for making kefir. Metals besides stainless steel can react with kefir.
- Half-gallon mason jar with lid (I like these plastic lids for my wide-mouth mason jars)
- Medium-size bowl
- Strainer or colander
- Spoon or rubber spatula
- Smaller jar with lid for storing grains in the refrigerator
How to Make Milk Kefir
I’ve included a printable recipe card at the end of the post. Here is the process:
Step 1 (Day 1) – Combine Milk and Kefir Grains and Ferment
First add your kefir grains to a clean half-gallon mason jar.
Pour fresh milk over the top of the grains to the 6-cup mark on the jar. (If you want to make more or less kefir at once, just use the same grain-to-milk ratio.)
Place a plastic lid on loosely so it can still breathe.
Then place your jar out of direct sunlight. I just cover mine with a towel on the counter so I don’t forget about it the next day.
Allow the milk to ferment for 24 hours, or until it has thickened to the consistency of heavy cream or a thin yogurt.
Step 2 (Day 2) – Strain Grains Out of Fermented Kefir
Place a colander over a bowl and strain your kefir through to remove the grains.
Use a spoon or rubber spatula, if needed, to help the kefir through.
Use the grains to start a new batch of kefir right away. If you want to wait until another day to make more kefir, simply store the grains in the refrigerator in a small jar of milk.
Pour your kefir back into your same half-gallon jar after you’ve strained out the grains…
And replace the lid.
Step 3 – Second Fermentation
Your kefir is ready for consumption after step two. However, if you want to take the process a step further, you can do a second-fermentation without the grains. This will increase the nutritional benefits and make the flavor a little more mild.
All you have to do is allow the kefir to sit at room temperature for another 6 hours with the lid on loosely before you secure the lid snugly and store your finished milk kefir in the fridge. That’s it!
Tips for Making Milk Kefir
- Your grains will multiply over time, but using too many at once to ferment a small amount of milk won’t work as effectively. You can give extra grains away to a friend, blend them into a smoothie, feed them to your dog or chickens, or compost them.
- You can make a new batch of kefir with your strained grains every single day, or you can store the grains in the fridge in a smaller jar of milk between batches for a week or more (if the milk thickens in the fridge and you still aren’t ready to make more kefir, just strain and replace the milk so the grains don’t starve). When you’re ready to make more kefir, just pour the grains, milk and all, into your half-gallon jar and top it off with new milk as normal. The grains will multiply less quickly if they are often stored in the fridge, as the cold slows them down quite a bit. They will be happier if you make small batches of kefir more often rather than big batches less frequently.
- Your kefir should form in no less than 12 hours and no more than 48 hours. 12-24 hours is ideal. You can adjust either the amount of grains, the amount of milk, or the temperature of the room to help your kefir ferment more quickly or more slowly. Less milk, more grains, warmer room = quicker fermentation. More milk, less grains, colder room = slower fermentation.
I’ve included a FAQs sections after the recipe card, but I’m happy to answer any other questions if you leave them in the comments below.
If you make this recipe and love it, I would be so grateful if you would come back to leave 5 stars and a comment or review! Constructive feedback is appreciated as well. Tag me on Instagram @aberlehome to show me what you made!
How to Make Milk Kefir FAQs
1. What is the best milk for kefir?
Full-fat animal milk is ideal for thick, creamy kefir and happy grains. You can make do with a lower-fat milk if you need to. Pasteurized or raw milk will both work. Don’t use skim milk or ultra-pasteurized milk.
Any time you switch milk types, your grains may take a couple of batches to adjust to the change.
It is also possible to make kefir from plant-based milks, though I won’t go into that here.
2. How long does milk kefir last in the fridge?
It should last just fine in the fridge for two weeks, and maybe a little longer.
3. Why did my kefir separate?
It’s natural for the whey to separate from the solids in kefir, and it’s not harmful. I’ve noticed my kefir will always separate in the fridge if I use a lower fat milk. You can shake or blend it to help it come back together.
If your kefir is separating during fermentation, it’s over-fermenting. Either you’re letting it sit too long for the temperature of your kitchen, or you’re using too many grains.
4. How do I know if my kefir is bad?
If you see fuzzy or colorful mold, or the kefir has changed color or smells rotten, get rid of it. Remember, though, that the smell will be different and stronger than yogurt.
I’ve never experienced a kefir ferment going south or making us sick in the years that I’ve made it.
5. What happens if I drop my grains?
If you accidentally drop a grain on the counter or floor (I’ve been there!), don’t worry! You can give it a rinse in a strainer with clean, cold water, then place it back in milk.
6. How much kefir should I drink each day?
If necessary, you can consume kefir in very small amounts in the beginning to allow your gut to adjust to it.
I personally didn’t have any trouble drinking a full cup from the beginning. Some people enjoy drinking a serving of kefir daily.
7. What can I do with milk kefir?
You can drink it plain or stir in a bit of honey or maple syrup. It’s delicious with fruit, cold cereal, or my Homemade Cinnamon & Nutmeg Granola.
You can also blend it into a smoothie using ripe banana in the mix to add sweetness.
My favorite is to blend kefir with banana, flax seeds, cinnamon, and nutmeg. (I quite like the cinnamon/nutmeg combo if you haven’t noticed by now.)
Finally, you can often use kefir in place of buttermilk, yogurt, or sour cream in recipes (though heating it will kill the probiotics). I’ve even seen some delicious-looking kefir salad dressing, ice cream, and popsicle recipes online.