water kefir grains - speed of growth? change of conditions?

[Algoldor]

Hi to all,
I have received a new culture of water kefir grains (fresh in sugary liquid) around a month ago, it ferments great but no increase in weight. Could anyone suggest why is that so and how to make the culture to grow better?

Now more info. During my food hacking tour through Europe I got really nice grains of water kefir up or over to 7 mm size (2/3 to to a nickle size) which are fermenting very well but alas they do not seem to grow too much - increase their bio-mass/weight. I have started with 65 g (2.29 oz) on 18/8/2013 and I'm exactly on the same weight on 8/9/2013. I could see some of the grains either dissolving or forming very small grains on the bottom of the fermentation jar. I did one 6 l (7 qt) brew and one 2 l brew, in both cases using around 6-7% (w/v) of light brown cane sugar (organic) and very good spring water, fermenting at room temperature which in this case was within 20-30C (77-86F) oscillating during the day/night. All brews were nicely fermented and sparkling. I have the same info about the grains not growing from another fermentor/kvasir from Prague, Czech Republic, so temperatures around 5C less.

The only thing which I can think may be a problem is the high ratio of water kefir grains to the liquid/brew, in case of 6 l batch it is more than 100x more liquid that the culture. However for brewing with kefir whey, kombucha or yeast this ratio is still OK. I'm able to double the weight of both milk kefir grains and kombucha culture within month and half, here I do not see it happening.

Many thanks for any info, if you can share your way of brewing with this culture that would be great. I had it several times before and up to now it is the most problematic biofilm polyculture which I was working with but I really like it because of it's light flavor, sparkliness and suitability for vegans.

Sincerely from Kasiri, Jeju, South Korea,

Frantisek Algoldor Apfelbeck

[Algoldor]

I forgot very important part. I do partly anaerobic fermentation with the water kefir grains - leaving around 20% of air in the vessel, closing it tightly and opening it every day or every second day more or less.

I have got a note that source of nitrogen is needed to produce the dextran matrix (which is the composition of the grains), dried figs are suppose to be best - more info in these articles: Stacey & Stacey 1938 and Reiß (1990). Links to these articles are online here (in the article where I got the information from): http://brozkeff.net/2010/12/15/tibi-vod ... lastnosti/ (CZECH).

I am really curious about this issue.

[ChefSam]

Well, this is a really old post, but maybe someone's still having the same issues.

I've had nearly doubling of my water kefir grains volume every time I make a batch , at least when I don't forget about it and let them pickle themselves.

I read the grains are quite mineral hungry and seem to adore ginger, so I always put a slice or two of that along with a tiny pinch of natural (unrefined sea or himalayan) salt to your other basic recipes. I always add a slice of lemon to up acidity, add a little vitamin c and help prevent mold too. I reuse the ginger and lemon slice for a few batches, usually doing a secondary fermentation with flip top bottles to add a little carbonation.

Sometimes I add a little rinsed organic egg shell, but this always leaves a little filmy-ness from not quite dissolving, but if you don't have anything else around its a great source of the minerals that seem to keep them thriving and multiplying.