Kombucha is a living mushroom tea that has natural carbonates. This implies that it continues to ferment residual sugar even when in the bottle. As a result of this anaerobic fermentation sometimes as high as 3% alcohol if the kombucha brewery is not careful. For budding entrepreneurs looking for FSSAI compliance of 0.5%, here are a few tricks that you could adopt.
- Reduce the fermentable sugar to zero (This is one reason why American Kombucha is so tart). If there is no fermentable sugar, then there will be no alcohol production post-bottling. This has the added advantage of preventing bottle bombs due to excessive carbonation.
- Add unfermentable sugars: Lactose and Malto-dextrins are used by kombucha brewers to add to the mouthfeel and slight sweetness without adding to the alcohol.
- Use artificial sweeteners like Stevia. These add to the sweetness that Indians love without the risk of ethanol production
- Filteration: passing kombucha through a 0.5-micron filter allows you to prevent any yeast cell (roughly 2-4 microns in size) to pass into the bottle. This way one can easily do secondary flavors and conditioning without the risk of alcohol production. Some brewers have tried cold crashing and using a fining agent to remove the yeast cells from kombucha. However, it cannot remove 100% of these cells and hence is only an incomplete solution prone to risks.
- Pasteurization: You can use a milk pasteurization kit. It boils your kombucha and rapidly cools it down with a minimal change in flavors. The downside is that one has to force carbonate kombucha after that.
- Kegging: One of the safest ways to ensure that alcohol content is close to permissible limits is by supplying kegs. Use the carbonation lid and pump some oxygen from the tank. It will help in introducing O2 to metabolize any alcohol while not impacting the taste.
- Another problem with commercial fermentation tanks is that they are deeper than the glass bottles used to make kombucha at home. This means that the liquid has lesser chance to oxidize and burn off the alcohol produced. Use the carbonation stone to diffuse oxygen in deep SS concial fermentation tanks. This has a stone with small 2mm pores. These microbubbles of oxygen get readily dissolved in kombucha and will burn off any ethanol.