Both drinks are fermented using a SCOBY (Symbiotic Culture of Bacteria and Yeast). They can both be made in your home kitchen with relatively little equipment, in a relatively short amount of time. The taste of both can be further enhanced by flavouring with berries, botanicals or spices.
Producing commercially is quite a different matter. Here the master brewer has to be very skilled at stabilising the product through the processes and procedures they follow. For this reason, one needs to be wary of buying commercially produced kefir and or kombucha, due to the temptation of producers to filter/eradicate any live bacteria in order to make the product more stable and to have a longer shelf life.
Water Kefir and Kombucha are both suitable for lactose intolerant, vegan, or persons intolerant to dairy products and contain a good dose of probiotics for those seeking a healthy drink. However, one needs to look at the ingredients, the process and the taste to understand the main differences.
While both drinks are fermented using beneficial bacteria and yeast, Kombucha is fermented tea and therefore contains caffeine. So, those consumers concerned about caffeine intake, should avoid it.
Kombucha is produced by first brewing either black or green tea in a solution of sugar along with a SCOBY. During the fermentation process the bacteria and the yeast in the SCOBY work together to convert the alcohol and sugar into mainly beneficial organic acids. This solution can then be infused with berries or botanicals. The end result is a sour tasting, slightly fizzy drink, which contains live cultures that are good for the gut and digestive system.
Kombucha will generally have a different mouth feel to water kefir – being more acidic, sometimes, even vinegary compared to the more fermented overtones of Water Kefir.
Water Kefir is made by fermenting white, crystal like water kefir grains, also referred to as a SCOBY (but appearing different from the pancake like kombucha SCOBY) in a solution of activated water and sugar (preferably organic raw cane sugar).
During the sustained fermentation process, the yeast continually ferments, turning sugar into alcohol, for the bacteria, in turn, to convert the alcohol into healthy acetic gut friendly acids. This means that water kefir will become more and more sour during this process, as all available sugar is used up. The bacteria’s ability to quickly convert alcohol into acetic acids means water kefir is low in alcohol, usually between 0.5%-1% ABV. This is no more than you will find in a jar of sauerkraut. Berries and botanicals and or spices can also be added in a second fermentation process.A well-made water kefir should have enough residual sweetness to be enticing and enough acidity to be lively. Striking the right balance between sweetness and acidity is the skill of the Master Fermenter.