What is the proper way to store SCOBY for periods over 3~4 months? I've stored some discs/plates of SCOBY in the fridge (not freezing temperatures) on its own fermented tea, but after 3 months when I picked it up to do some kombucha, it did not ferment the tea. I've used the same process for periods of 1 month and the fermentation went well.
This site recommends you keep culturing for less than 6 weeks. For longer, they recommend two options.
- "Feeding" the scoby every 4-6 weeks, where "feeding" consists of draining off the existing solution and adding fresh, sweetened tea. That site also recommends adding sugar over nothing.
- Dehydrate the scoby (see the link)
However, neither option claims to work more than 3 months.
Having said that, I have used a scoby that sat for over a year without any feeding or dehydration and it worked fine. It was just in a glass jar with about a quart of kombucha in the back of my fridge. This is probably abnormal though.
That same site also shows you how to recognize a healthy scoby. I would highly recommend just getting another scoby if yours looks unhealthy after extended storage. Otherwise, if it looks healthy, give it a shot.
My ginger beer SCOBY has grown in a jar for over 9 years. If kept hydrated and fed (with ginger and sugar and occasional fresh lemon juice) it seems to keep well enough. If I do not produce/bottle ginger beer for a time then I rinse the SCOBY monthly (or so) and replace the old water which removes any build up of by-products. I still use the orginal "plant" to ferment ginger beer and it has grown considerably over the years.
Of course, as it grows I divide it. I think this is about the twentieth division - necessary to stop the RGB SCOBY from taking up too much of the volume of the 5L glass demi-john it is stored in. Sometimes I leave a part of the SCOBY in the divided liquid but without feeding it. It seems to be relatively stable if the solution is slightly acidic (pH 5 or less) which happens naturally in ginger beer fermentation. The lactic acid solution naturally produced does not seem to get overly sour and does not seem to pickle the SCOBY. Such SCOBYs in solution seem to "hibernate" when there is little or no nutrient but I have brought them back to activity by changing the water and adding sugar/ginger, sometimes after 5 or more months neglect.
I have dried some of the "opaque jelly" grains from such a division for storage. The grains change from an opal white colour to a more yellow/brown colour as they dry out. I have kept the dried grains for about 18 months in a sealed bag in the fridge and successfully re-hydrated the grains and used them to ferment. The grains tend to loose the colour when fully hydrated.