We conducted a very informal, and not especially well-replicated (2 replicates in each group) experiment to compare how a kombucha culture forms, and, to some extent, behaves when started from a piece of culture and some kombucha liquid versus when started from a bottle of good kombucha. What follows is a photo journal of our ”results”.
4 jars of sweet black tea
The 2 jars on the right side of the picture below received a piece of kombucha culture and 2 dl of finished kombucha.
The 2 jars on the left side of the picture below received 1-2 bottles finished Roots of Malmö ”Naturell” kombucha (1 bottle per liter sweet tea). Kombucha was 2 -3 months old and purchased from our closest ICA (ICA Möllan).
AFTER 9 DAYS
We see little difference. Both are forming new cultures on the surface of the liquid.
We really don’t see much difference between the cultures at this point.
When i got into the brewery on Monday, I noticed I forgot to empty and clean the containers I used to sample our kombucha from the tanks on Friday, and, as usual a little pellicle has formed on top:
AFTER 1 MONTH AND 2 BREW CYCLES
We do see some difference, primarily that the culture started from a piece of culture remains floating and as such is getting thicker:
While the cultures started from bottles, sink each time the culture is renewed and as such each ”daughter” (as they are sometimes called) is quite thin.
In this picuture, you see the sunken ”mother” culture piece, and the newly formed ”daughter”.
After 1,5 months and 4 cycles, both cultures remain floating when we start the new batch and now the cultures appear largely the same.
AFTER 2,5 MONTHS AND 5 CYCLES
They look very much the same.
We also measured pH, and while they varied a bit (2.68 – 2.83), they did not vary across treatments (with-scoby average pH 2.74; from-bottle average pH 2.75; note this is very low for kombucha pH; these kombuchas would be too strong and dry to make a very tasty beverage on their own).
Finally I got tired of this experiment and left these jars alone for a few months. I have kept these cultures alive, and they continue to behave the same. There is no perceivable difference in the amount or appearance of the culture, or in the taste of the brew.
Conclusion: You can start a healthy culture from a bottle of store-bought kombucha (provided it is whole-brewed, unpasteurized, and unfiltered).