My "Kombucha Coffee" Experiment

Well today i decided to try my Kombucha Coffee idea. I have read in many places that the caffeine in the tea is "used up by" or "is fuel for" the bacteria, so i thought that considering coffee has more caffeine than tea i would try it out. I made a pot of VERY strong coffee(about 6-8 coffee "scoops") for a 4 cup coffee maker. I added the coffee to 1/3 cup white table sugar in a 1 quart mason jar and i inoculated that with Kombucha from 2 different brand names of raw kombucha GT's and Vibranz.

I used a mix of the two because even tho they have the same yeast strain S.Boulardii they use two different bacteria strains One uses Lactobacillus bacterium and the other uses Bacillus coagulans GBI-30 6086.


What i hope to find out from this is:

One will it grow a Scoby if coffee is used in place of tea?

Two will the end result be drinkable?

Three if it does form a Scoby and that Scoby is used in a Second jar of coffee/sugar mix will that be a more drinkable product(i expect the first batch to be highly acidic due to the time needed to grow a Scoby 20-30 days on average)?

Four will Kombucha made with coffee even work at all in anyway?



Feel free to comment in any way, if you have tried this, if you think its a cool idea, if you think it will be a total flop. I am interested in input and ill let you know what results i end up with.


I also have 3 jars made with 3 different Herbal Tea Blends and standard tea added to answer the same questions above. In these Jars i used 3 different sugar sources, One white sugar, one molasses, and one honey. So with what i have going right now i have the possibility of ending up with 6 Scobys. I like to experiment what can i say!

Well this one has about 2 inches of foam on top of it, looks like i am fermenting beer instead of kombucha lol.

Bamp! Any updates on your kombucha coffee? Has it formed a mother yet?

AntX said:

Bamp! Any updates on your kombucha coffee? Has it formed a mother yet?

Click to expand...

Nope no mother that i can see, but then again that could be due to the dark nature of the coffee. It does however smell amazing!

Vance, i am very interested in your experiment and hope to see your continual posts. I am performing similar research on Saccharomyces cerevisiae for my seminar to get my BS in chemistry anf considered graduate work on the strains in kombucha.

I would suspect your experiment should go pretty well for the coffee as long as you took into account the fluxuation in pH due to the coffee addition, which should be around the pH i think your aiming for (~5%). As far as the sensory evaluation, i am a little skeptical how the stale coffee flavor will interact with the produced acetic acid(i think that is the byproduct of kombucha strains?). Should be interesting to see how it turns out, but i would not be surprised that it turns out rather successful.

P.S. I enjoyed your thorough analytical review.

jondthechemist said:

Vance, i am very interested in your experiment and hope to see your continual posts. I am performing similar research on Saccharomyces cerevisiae for my seminar to get my BS in chemistry anf considered graduate work on the strains in kombucha.

I would suspect your experiment should go pretty well for the coffee as long as you took into account the fluxuation in pH due to the coffee addition, which should be around the pH i think your aiming for (~5%). As far as the sensory evaluation, i am a little skeptical how the stale coffee flavor will interact with the produced acetic acid(i think that is the byproduct of kombucha strains?). Should be interesting to see how it turns out, but i would not be surprised that it turns out rather successful.

P.S. I enjoyed your thorough analytical review.

Click to expand...

Well i checked the jar and there is no scoby growing at all but it does taste rather good as you pointed out coffee is acidic as is so the flavor complements it well at least in my personal opinion and i detect no "stale flavor". Acetic acid is one of the acids produced along with gluconic acid and you can control which acid is produced the most by changing the sugar source. For Example Glucose / Dextrose (corn syrup) kombucha fermenting all Glucose will produce almost all gluconic acids with very little acetic acid. So you can to an extent control the flavor profile, i personally use a 5 to 1 ratio 5 oz Dextrose 1 oz Sugar in the raw.

this might be better tested is you add an actual mother instead of trying to grow a mother from scratch.

Tinga said:

this might be better tested is you add an actual mother instead of trying to grow a mother from scratch.

Click to expand...

good idea!

I've thought about trying coffee instead of tea, but haven't done it yet. I'd like to see how yours turns out.

Tinga said:

this might be better tested is you add an actual mother instead of trying to grow a mother from scratch.

Click to expand...

They call it Koffuccha, actually!

Still interested! How is the kombucha going vance? And I agree with Tinga. It is always good to have a healthy starting colony before testing

Any updates on the kombucha experiment?

My interest is piqued as well! Naturally being more of a coffee drinker than tea, this is relevant to my interests.