How to Make Water Kefir

03 May 2022

Two jars of fermenting water kefir
Two jars of fermenting water kefir

Water Kefir is a one of the healthiest probiotic drinks out there, especially if you make it at home. It is my personal favourite probiotic drink and I drink it every day. Brewing it is pretty straightforward and requires a fairly minimal setup and ingredients. The below information details my method of brewing water kefir.

Table of Contents

1. The Basic Idea of Water Kefir

Brewing water kefir requires three components: water kefir grains, water, and sugar. Water kefir grains are clusters of bacteria and yeast that look like little blobs of jelly. You place them in a jar of water and add sugar. The microbes from these grains eat the sugar and multiply themselves. The kefir grains also grow and multiply. After a few days or so of fermentation, the water will be filled with these microbes, and you have a fresh probiotic drink to enjoy.

After separating the water from the grains, you may drink the water whilst re-using your grains to brew another batch of kefir.

2. How to Get Water Kefir Grains

You need to buy them from a supplier or get some from a friend. You should be able to buy organic water kefir grains on the internet in most countries, you can get them shipped to your door.

3. Ingredients and Equipment

As I mentioned, water kefir ferments with water kefir grains, water, and sugar. I will go into detail about these ingredients, as well as specifying other things you'll need.

  • Water kefir grains - see above.
  • Water - preferably not tap water. Tap water usually contains substances, such as chlorine, which will negatively affect the microbes in your kefir, and possibly even kill them. I use glass-bottled spring water for my kefir. The water is clean, and the glass bottles are useful for keeping the kefir in. I use still water.
  • Sugar - essential for the fermentation to happen. Ideally, you want to use organic sugar in your kefir ferments. Regular refined sugar may work, but is likelier to be contaminated with chemicals that damage the grains.
  • Molasses - kefir grains thrive in mineral-rich water. Adding molasses to a kefir ferment is a great way to supplement minerals into the water. Molasses, a thick treacle that is the byproduct of the sugar refinement process, is rich in minerals. I highly recommend using molasses, though it may not be necessary if you are using a mineral-rich water. I suggest buying an organic product.
  • Glass jars - to brew your kefir in. Size and number of jars will vary depending on how much kefir you want to make. I brew kefir in a couple of two-litre glass jars, for a total of four litres of kefir.
  • Swing-top bottles - optional, to do a second anaerobic fermentation with (see below). During this process, the kefir becomes carbonated. A good swing-top bottle can withstand a lot of pressure from carbonation. Alternatively, if you buy glass-bottled spring water, you could use those bottles for the second ferment.

4. Activation Process

If you got your water kefir grains delivered in the post you will need to "activate" them. Because the grains have been sitting in an envelope and not in sugary water the microbes are "asleep" and you need to reawaken them.

To do so: Place your grains in a jar and fill it with some water. It is often suggested to use roughly 250ml of water per 20g of grains. Add about one tablespoon of sugar per 20g of grains to the water. Do not cover the jar with a tight lid. Instead, use something like a paper town to cover it, fastened onto the jar with an elastic band. This allows for an aerobic (in the presence of oxygen) ferment.

Leave the solution to sit at room temperature for a couple of days, after which the grains will be activated. You may discard the water, but the grains will be used to start brewing batches of kefir.

If you know the grains you have are awake already, for example your friend gave you some straight from a fresh fermentation, you don't need to activate them. They are already awake.

5. First Fermentation

Place the kefir grains in a glass container, fill the container with water, and add sugar. Mix the sugar into the water well. The standard recommendation is: per 20g of grains, use 500ml of water and a tablespoon of sugar. This is good to start out with, but as I have done more first ferments and my grains have grown and replicated, I use many more grains and more sugar than that. Once you have grown enough grains, you can experiment with using more grains and sugar too, as this can add a lot more probiotic value.

I also add molasses to my first ferment. I add about half a tablespoon per litre of water, and I mix it in well.

The first ferment is aerobic, in the presence of oxygen, so don't cover the container with an airtight light. Like with the activation process, cover the container with a paper towel or cloth, fastened onto the jar with an elastic band.

The amount of time needed for the first ferment various, usually you will need at least two days. If you have done numerous first ferments and have many grains, you probably won't need more than two days unless the room temperature is cold.

To get an idea of my own current process: I have a two-litre glass jar I use to do a first ferment. In the water I mix in six or seven tablespoons of sugar, and a tablespoon of molasses. I have over 100g of grains in the jar. I let the first fermentation water sit for around two days.

Once the first ferment is finished, separate the water from the grains. You then re-use the grains to start another first ferment, in a continuous brewing process. You may drink the water, or use it to start a second ferment (see below).

6. Second Fermentation

A second fermentation will increase the microbe content of the kefir and carbonate it, improving the taste and probiotic value.

Take the water from the finished first ferment and put it in a sealed glass container. This could be inside a swing-top bottle, or a jar or glass bottle with an airtight lid. Swing-top bottles, designed to hold carbonated beverages, are recommended. Alternatively, if you are not bothered about carbonating the kefir, you can just do the second ferment open air like the first ferment.

To carbonate the kefir, you must ferment it in an airtight container from which the carbon dioxide gas produced by the microbes cannot escape.

Before sealing the container, add a bit of sugar in, perhaps a teaspoon or two, to keep the microbes fed during the second ferment. Don't add molasses to a second ferment, the water will have enough minerals already from adding it during the first ferment. You may also add some fruit to flavour the drink. I like to add slices of lemon and orange. Finally, if you have enough grains from doing many first ferments, I suggest adding roughly a teaspoon of grains into the second ferment water. This helps speed up the fermentation and improves the kefir's probiotic value.

I usually allow two days for the second ferment. Depending on the climate you're in, you may need more or less time. It's up to you to see how your kefir reacts.

You may wish to "burp" your kefir occasionally to release some gas, preventing the carbonation from getting excessive. For example, I may open the lid on a bottle of second ferment kefir one day after starting the second ferment, before resealing it. Again, experiment with this yourself and see how often or not your kefir needs to be burped. In warmer climates, the kefir can carbonate very quickly. Either way, take care since too much pressure can cause explosions.

I wrote a post about how to achieve a speedy second fermentation. You can read it here: Water Kefir Fast Second Fermentation.

7. Storage

As I mentioned, fermenting the water kefir in glass containers is best. The kefir should be kept out of direct sunlight and at room temperature. Some may wish to use an electric heating blanket, as suggested in my fast second fermentation article.

During the second fermentation, I keep the fermenting bottles of kefir in a box covered with a towel. There is always a slight chance of explosions, so don't place the kefir in the open, such as on a kitchen counter, as flying broken glass cloud hurt you and others.

You may place the first ferment kefir in the open. Being an aerobic ferment that is not carbonated, there is no risk of explosion.

8. Cleaning and Contamination

Occasionally I take the water and grains out of my glass jars to clean them. I rinse them with some warm clean water and dry them. There is no need to sterilize your glass equipment, rising well in water is enough.

Some people suggest rinsing your grains in water between batches, but I have not found this necessary.

It's possible, but highly unlikely, for kefir to get mouldy. Kefir is highly resistant to contamination from external microbes, but it's good to keep an eye out for signs of mould. White froth on the surface of the water is not mould, it's just the result of yeast growing, which is perfectly healthy. After many months of brewing my own kefir, I've never had mould problems and most people don't.

If mould starts growing, I would suggest throwing out the water and getting new grains. You don't want to risk using contaminated grains, even if you don't see mould on them.