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In this post I want to share one of my smaller long-running experiments with milk kefir grains. This is about my experiments to turn milk kefir grains into consuming only sugar-water. It’s been going for almost four years now. It’s not yielded super exciting or revolutionary results. I’m sharing it anyway to explain what the process of messing around with new cultures is like.

What did I do?

I used milk kefir grains to ferment sugar water and fruit juices and tried to see if the result was worth drinking.

I did that because when I started out, I had a lot of milk kefir grains and no water kefir ones. I didn’t want to shell out $20 for the new culture. I figured it would be worth the attempt training my existing grains.

Instructions: Take a spoonful of milk kefir grains. Dissolve all the grains in two cups of lukewarm water. Gradually dissolve mineral sugar (ideally, but any sugar will work), a spoonful of it. Dissolve additional sugar every couple of days. How much? It depends. Taste the ferment every time, and if it’s gotten too sour, add additional sugar. Sourness means the ecosystem has run out of energy source, and has the capacity to process more. Adding too much sugar in one go can mess up the osmotic pressure of the cells and kill them. Alternatively, it can introduce pathogens that end up contaminating the drink. Therefore, a good balance is necessary.

Sugar is just carbon source for your culture, as carbs are to us. It will also need a nitrogen source, just as we need proteins. For that, you can either use coconut water or carrots. A couple of slices of carrots, or few spoonfuls of coconut water should do the trick. Some people also use clean potato slices, but you decide if you want your drink to have raw potato juice in it.

What to expect

Unlike water kefir grains and milk kefir grains, these grains will not multiply or increase in volume. That’s okay, they’ll still keep fermenting the sugar and produce your soda. Imagine them as dairy cattle that gives milk but doesn’t multiply. The color of the grains will change from white to translucent to light brown and eventually dark brown, reflecting the nature of the new source of carbon and nitrogen.

What to do with it

It is consumed exactly like water kefir, which is like a home-made soda. It will get quite sour, and it will get fizzy. You can add additional sugar for sweetness, or fruit juices for flavor. It can also be used for cooking. If the taste is a little off, it might not be unsuitable even as vinegar, which is what you can do with semi-failed ferments.

Other considerations: A risk with this sort of experiment is that the transfer might not work straight away and will probably need a couple of rounds of attempts to complete the transition. You might need quite a lot of milk kefir grains to help with the transition.

This is an ecosystem of microbes, and we’re getting them to eventually adapt to a new source of food. We are training them to be comfortable in their new surroundings. It’s important to be patient and let them adjust to their new ecosystem.

Once the culture is completely at-home in the new environment, we can drain out your soda, and add additional sugar-water-fruit to begin a new batch. Our ‘cattle’ are now trained on a new source of food, moving from lactose to glucose!

However, they won’t grow or multiply, so they can be quite precious. Because there’s always some loss during the filtering process, we must be careful on when or where you use these.

It’s possible the container will get a ‘SCOBY’ or biofilm on top of the ferment. It’s not an essential part of the process, and can be safely disposed.

Final thoughts

A jar of sugar-water a source of nitrogen (carrot, fruit juice, etc) can create an appropriate microbial environment naturally, and could kickstart a fermentation culture out of thin air. It doesn’t always need the kefir ‘grains’ or start liquid. However, that can be dangerous because that could also host harmful pathogens and cultures we don’t carefully control for. Before we try these experiments in the wild, it’s important to understand what we’re doing and what the risks are.

What I’ve explained above is a great advanced technique to explore new frontiers in fermentation and adapt existing cultures to new food sources. As always, it’s important to understand the biochemistry of what’s happening and the risks one is taking. We must not unnecessarily endanger the health of our friends or family without fully comprehending what’s going on.

However, with proper knowledge, these experiments can give us bio-cultures and techniques literally unique only to us. That can be a rewarding experience by itself. Have fun experimenting!