How to Make Kefir – How Fermentation Works

If you want to find out how to make kefir, it helps to know what the kefir is doing when you leave it to brew. The brewing process is called fermentation, and it’s really important for making all kinds of things, including beer, bread and yogurt! In this article, we will explain what kefir grains are doing when you leave them alone to brew (or as a biologist might say, to ferment)

Now there’s going to be a bit of science in this article! But don’t worry – we’re going to make it really easy to understand.

The first bit of science is this:

Everything we do requires energy. Thinking requires energy, breathing requires a little more and jumping around requires more still!

That wasn’t too bad, right? – so let’s look a little closer.

Just like a car or an aeroplane, the human body needs fuel to be able to do anything – but rather than petroleum based fuels, our bodies use food! Food is taken into our bodies and broken down into tiny particles that can be converted straight into energy. First our teeth break our food up into smaller pieces, and then our stomachs churn the food around to break it up even more.

While our teeth and our stomach are breaking the food up, special particles made in our bodies called “enzymes” help to break food particles into even smaller pieces. There are lots of enzymes – each made to help break down a different kind of food. When the enzyme finds the kind of food that it is good at breaking down, it breaks off the tiniest possible pieces so that the food is separated into its simplest ingredients (sugar, fats, proteins, vitamins, and so on – everything on the “nutrition information” panel on food packaging!)

The easiest food to turn into energy is sugar (which is why we sometimes get a “sugar rush”!). Most foods contain sugar, so when we digest food our enzymes help free up lots of tiny sugar particles to be turned into energy. Our body does this by performing a chemical reaction called respiration, which turns sugar and oxygen (from the air we breathe) into pure energy and carbon dioxide. That is why we breath out more carbon dioxide and less oxygen than we breath in. We use the energy produced to think, move, breath, learn how to make kefir, or do anything else we might need to do.

The bacteria and yeasts that make up kefir grains also need energy to live, which they also get from sugars. They mostly do not use respiration like we do though, and so don’t really need oxygen. They eat up sugar and then turn it straight into energy and alcohol, using a process called fermentation. This means that when you leave water kefir in some sugary water they will be using up the sugars and producing alcohol, in order to release the energy they need to grow and reproduce to make more grains!