Home made soft drinks with water kefir

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Zasso Nouka
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Re: Home made soft drinks with water kefir

Post by Zasso Nouka »

Thanks Paradoxbox,

Got the milk kefir grains sitting in some whole milk right now, they seem really genki.

I only ferment the water kefir for out 15 - 18 hours anyway, sometimes it goes for as long as 24 hours if I forget. I reckon you are right about the acid in fruit juices breaking the grains down, citrus juices turn them to slush very quickly and you are left with a disgusting mess. When we want a citrus flavoured brew we add the juice after it's finished.

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Re: Home made soft drinks with water kefir

Post by paradoxbox »

I've done some experimenting with the water kefir;

It seems that the kefir grains may prefer a slightly alkaline environment than certain tapwaters provide? I have started putting in a small sprinkle of baking soda into the mix and it has increased the speed of the fermentation.

The kefir grains also seem to prefer natural sugars like raw sugar or brown sugar, rather than white cane sugar, but this is not a scientific observation - my house is still quite cool inside so it may have just been random temperature fluctuations causing the ferment to accelerate on the days I used natural sugars.

For growing the grains quickly, white sugar and a fairly cool temperature seem to be ideal. When the mixture gets too warm it seems the fermentation becomes much more vigorous at the expense of grain formation. Again not scientific but seems to be the case for my batch of grains. I left a 1.5L bottle of water mixed with 1 cup of sugar on the countertop and the temperature was a little over 9c. The grains occupied the bottom 1/4 of the bottle when I left it - 24 hours later they had multiplied to occupy more than 1/3rd. Pretty neat :)

I wonder if these can be used for bread baking in some way?

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Re: Home made soft drinks with water kefir

Post by gonbechan »

paradoxbox wrote:
I wonder if these can be used for bread baking in some way?
Your wish is my command..

Water-kefir sourdough bread

And for the milk Kefir:

HOW TO USE KEFIR AS SOURDOUGH

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Re: Home made soft drinks with water kefir

Post by Zasso Nouka »

So we can make probiotic bread from these as well, that's pretty awesome
paradoxbox wrote:I've done some experimenting with the water kefir;

It seems that the kefir grains may prefer a slightly alkaline environment than certain tapwaters provide? I have started putting in a small sprinkle of baking soda into the mix and it has increased the speed of the fermentation.
Interesting discovery man, I know our well water is acidic because all our soil is. Might try adding a bit of baking soda into each brew then.

paradoxbox wrote: The kefir grains also seem to prefer natural sugars like raw sugar or brown sugar, rather than white cane sugar, but this is not a scientific observation -
I think it because the brown sugars contain more than just glucose and provide the kefir with minerals and other nutrients as well.

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Re: Home made soft drinks with water kefir

Post by Zasso Nouka »

Paradoxbox is our milk kefir expert, hopefully he'll be able to help you.

I've only been making it for a while after he sent me some of his grains so don't really have much experience. My water kefir grains did loose their mojo at one point and I had to go back to a stock that I'd dried out and frozen, it took them a while to regain their health after thawing out but given some TLC they came back to life. Maybe just starting again from scratch will sort your issue out.

Hopefully Paradoxbox can shed some further light on the problem.

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Re: Home made soft drinks with water kefir

Post by paradoxbox »

Thanks for the street cred ZN!

I think if your grains are not doing so well any more you might just try smashing a few of them until they're very fine particles. Don't wreck them all though.

The grains are just colonies of bacteria and yeast clinging to eachother, so it does not really matter if you smash them. By smashing them you're likely to expose still living or dehydrated cells to the milk, whereas if you didn't smash 'em the fermentation would probably just stall out. Put them back in a small amount of milk (Like 50ml or so), ferment for 12-24 hours and see how they look. Change the milk out regularly so the grains can feed. The smashed grains should start rebuilding again and multiply and get bigger after a few days. The bigger the grains are, the better since they'll have more surface area for fermenting - but if the grains seem "dead" smashing them should revive them.

If your grains just won't make the milk frothy anymore it is highly likely that some other kind of yeast and or bacteria have contaminated the culture.

If you don't mind a runnier product, you can drink this safely, but if you want to have the thick frothy stuff forever, you need to keep a set of grains dried out and in a sterile jar or container to use if your grains stop working the way you want them to.

I've never heard of grains actually dying except for if you heat them too much. Anything more than around 40c is pushing the limits and will probably kill them. If you wash the grains do it with tepid water. Contrary to common internet opinion, washing the grains does not stop them from fermenting milk, every cell of a kefir grain is a fermentation factory that can multiply into billions of cells in a short time if it's given food. Washing the grains will probably also help prevent infection from acetic or other bacteria that could mess with your desired ferment.

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Re: Home made soft drinks with water kefir

Post by paradoxbox »

Make sure you're using non ultra-high-temperature pasteurized milk. UHT or ESL (Extended Shelf Life) milk is the most common milk in Japan and you will have to actually search for milk that is not pasteurized in this way. Full fat or nearly full fat milk is also good, but it may be hard to find full fat non-UHT milk. I use milk that's pasteurized at 66c for 30 minutes and it works really well for kefir and cheese making.

The ultra high temperature physically destroys many important proteins and other important stuff in the milk that the kefir bacteria need as food.

I would keep 3 batches for experimentation: one batch should be kept as original stock and kept very sterile, the others two can be used for experiments and regular consumption.

I had a batch of kefir made from powder a few years ago which I kept alive for 2 or 3 years and managed to get some small grains out of that, but you're right it is a lot easier to just start off with the the big grains in the first place.

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Re: Home made soft drinks with water kefir

Post by paradoxbox »

One thing I thought of last night when I was making my kefir, have you tried sealing the bottle it's fermenting in, and shaking it often? Especially just before serving. I found that this puts a lot of carbonation into the milk and makes it very frothy and more yogurt-like.

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Re: Home made soft drinks with water kefir

Post by paradoxbox »

Put em in the fridge til Monday, that will stop them from over-fermenting.

I found out if you leave them to ferment at room temp too long the acidity or alcohol levels really hurt the grains. It took me a few weeks to nurse the grains back to health.

If the guy is making mozzarella or hard cheeses with that milk, it should be totally fine for kefir :)
If it is just cottage cheese he is making, you can try it but I would only put half my grains in it to see how it will turn out.

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Re: Home made soft drinks with water kefir

Post by paradoxbox »

Do you have a コープ supermarket in your area? They definitely sell low temperature pasteurization milk. Even if it's not on their shelf, if you ask they will stock it for you.

You can ask around to your local supermarkets for teion sakkin gyuunyuu / 低音殺菌牛乳.

If they don't have it, they will probably order it since the same companies that make UHT milk also make non UHT milk.

It is a bit more expensive at around 250 to 320yen per litre. I buy mine via coop delivery, around 4L per week, more if I'm on a cheese making binge.

Make sure to tell the Italian guy once you've got a supply of good milk!


UHT milk, as you've mentioned, seems to starve kefir grains.