In order to make cultured kefir milk, you must start with LIVE kefir grains. These grains, which are clusters of yeast and live bacteria, have been cultured for thousands of years. They multiply when they are put in milk and kept at room temperature.
Kefir grains ready to culture
As you can see from the picture, the kefir grains look like cauliflower. Kefir is a living organism, so you must care for it carefully if you want it to thrive. Here are a few rules:
*Kefir does not like metal. Only use wood or plastic utensils when working with your kefir.
*UV rays harm kefir, so keep it in the dark as much as possible. As you can see, I have a glazed crock with a lid (not airtight) that I keep my kefir in when it’s culturing the milk. I also use glass quart jars when storing the grains in the fridge.
*You must use very clean utensils when working with kefir because it will be culturing at room temperature. You don’t want to be growing anything BUT kefir bacteria.
Equipment
You do not need a crock, but if you have one, you can leave your kefir out on the counter while it’s in the milk. If you don’t have one, you can use a glass jar kept in a dark cupboard.
Step 1: Put about 1/4 c. kefir grains in 1 qt. milk. You can use any kind of milk, even soy or rice milk, but the kefir might not multiply in lactose-free alternatives. If you have access to raw milk, you’ll be amazed at how quickly the kefir grains multiply.
Milk added to kefir grains
Step 2: Cover the kefir milk loosely (your main goal is just to keep light and dirt out). If you are culturing your kefir milk in a glass jar, store the jar in a dark cupboard. Just don’t forget it’s there!
Step 3: Kefir likes to move around, so stir it occasionally with a clean, non-metalic spoon. Or swish it around in the jar. You’ll notice that the kefir grains float, and they begin to form clumps in the milk. This is a good sign! This means your kefir grains are doing their work. They’re breaking down the lactose and the proteins, and forming good, healthy bacteria colonies. You will also notice that the kefir milk smells yeasty. This is what you want!
Kefir, 8 hours cultured
Step 4: The kefir milk is done in as little as 12 hours, especially if the weather is warm, and as long as 24 hours. The whey may begin to separate. Just stir it gently to incorporate it again. How do you know when it’s done? Mostly, you will learn by experience . The kefir milk becomes more tart as time goes on (like buttermilk). It can also taste like yeast, especially if it’s cultured for longer than 24 hours. I usually let mine sit the full 24 hours because I don’t drink it plain. If I were to use it on cereal, like many people do, I would strain it earlier.
Straining the kefir milk
Step 5: Using an impeccably clean plastic strainer placed over an impeccably clean plastic container, filter out the kefir milk, leaving the kefir grains in the strainer. The kefir milk will be thick like buttermilk. You may have to gently stir the grains around in the strainer to get the milk to go through. It also helps to stir the cultured kefir milk before pouring it into the strainer to “loosen” up any clumps that are sticking to the bottom of the jar.
Step 6: Use the kefir milk! I love to use the kefir milk in smoothies (1/2 c. kefir milk, 1/2 banana, and a handful of strawberries is great!), or in place of milk in almost any recipe (see my Sprouted Wheat and Kefir Bread recipe on this site).
Kefir milk, ready to store in the fridge
Step 7: If you’re ready to make more milk, just put the strained kefir grains in a new jar and start over at step 1. However, if you don’t need more kefir milk right away, you can store the kefir grains in the fridge. Simply put the kefir grains in a fresh jar with just enough milk to cover. As your kefir grains multiply, it’s a good idea to keep one batch of kefir grains working while another batch rests in the fridge. I have found it helpful to label the jar with the date (because I forget). You can store the kefir in the fridge for up to a month. It goes dormant at that temperature and won’t multiply. If you need to keep it longer than that, it’s a good idea to get the grains out of the fridge, bring them up to room temperature, and “feed” it with a little fresh milk. Then it can go back to sleep!
Step 8: When you’re ready to use the reserved grains, simply strain out the milk it was kept in and start over at Step 1.