brewing with kefir grains

[GeneDaniels1963]

I keep a qt of milk kefir going all the time, love the stuff on cereal and in bake goods.

For those who don't know, kefir grains are symbiotic colonies of yeasts, bacteria, and other odd stuff. Kept fed, they steadily grow. I decided to try fermenting with some. I am doing a test with a honey-based yeast starter (SG 1.050). I am hoping for some funky, 6%ABV stuff.

I have read somewhere that others do this, and like the results. But who knows. I figure it is worth a try. If the starter does well, and smells/tastes nice, I will do a gallon of juice.

 

[bmd2k1]

Dig kefir - typically Lifeway brand. Keep us posted [emoji111]

 

[GeneDaniels1963]

will do

 

[GeneDaniels1963]

So far, 1 week in, nothing. I don't know if that means the experiment is dead or what. But I will give it another week since I don't take up any real space.

 

[bernardsmith]

I've been experimenting with milk kefir grains and found that I was able to get them to ferment molasses that I had diluted to about 1.050 and the last reading I took after a week was 1.030 . They are still surviving in the alcohol and still pumping out CO2. But when I transferred some of the grains to some lemon juice with sugar they have not shown any activity. Here's the thing. Milk kefir grains really do not like every sugar that wine yeast like so for example, I don't know that kefir will ferment honey. But that said, note that I have been referring to milk kefir. There is a very different kefir which does not culture milk - water kefir and while you can acclimatize milk kefir to thrive in sucrose (I think it's fructose, not sucrose) you cannot then get those grains to work milk at a later time. You will have killed off the bacteria and the yeasts dedicated to lactic acid producton.

 

[wasully]

What's the pH of lemon juice? It might be inhibiting the yeast.

 

[bernardsmith]

Yesterday evening, the airlock dis show some signs of out-gassing. Did not see anything bubbling but the height differential in the S -airlock suggested that pressure was being exerted from inside the mason jar.
Checked the pH and it is reading 3.24 so it may be too acidic for the comfort level of the grains but remember that kefir is a complex scoby of many bacteria and about a half dozen or more different types of yeast in a complex "organism".

 

[GeneDaniels1963]

Well, I can call this experiment a failure. It's been going for 1 month and there has been very little "ferment." The wort is a bit sour, nicely so. And it may have a 1% or 2 of alcohol, but it will not work to ferment a cider.

Oh well, you never know til you try.

 

[bernardsmith]

There are two varieties of kefir. One is milk kefir and the other water. Milk kefir grains prefer lactose but they can be acclimatized to ferment simple sugars such as sucrose and fructose but water kefir grains cannot ferment lactose - and if you manage to get milk kefir grains to ferment say fructose, the yeasts involved in fermenting lactose will have been lost.
That said, the yeasts and bacteria as a colony are not able to get much beyond 2% but I would think that you can culture the yeasts you have in the grains to select out those cells that push the amount of alcohol higher, but you do that by gently giving the yeast more sugar to ferment and harvesting those that manage this and using those cells and their daughter cells to produce more alcohol. What I might do also is add some hops to kill of the lactic bacteria which in kefir don't compete for sugar but collaborate in the fermentation process. in other words you want to encourage the yeast to ferment the sugars and inhibit the bacteria in transforming those sugars into souring acids.

 

[GeneDaniels1963]

I think for now I will just look at other ways to sour my ciders

 

[WildFer(wo)menter]

Hi Folks!
[Note: this was all done as wild fermentation]

Thought I’d add my experience to this. Last year we fermented 1 gallon of cider with water kefir grains. With the same juicing batch, we did three other gallons, all different, as a compare-contrast. Here were our four different gallons:
- kefir added to freshly pressed juice
- plain freshly pressed juice
- brown sugar added to freshly pressed juice
- honey added to freshly pressed juice

In the order I listed them from top to bottom was the order they finished.

The kefir one stabilized fastest - and I wonder if it is because there were even more hungry yeasts in there than the other jugs - more yeast to sugar, rather than those sugar-added jugs, which had more sugar to yeast.

It tasted Ok, but bland. We weren’t inspired to do it again.