DIY Coffee Kombucha
Kombucha! What is it you ask? Kombucha generally refers to lightly sweetened, fermented black or green tea drinks, although in this post we are using a recipe to make a coffee kombucha. Kombucha has become more trendy in recent years as more people have become aware of the microbiome’s influence on our health and how probiotics may play a role. As a testament to this, Pepsi recently jumped into the kombucha game by purchasing the popular fermented beverage company Kevita® (see here). In our experience, these drinks usually costs at least $3 so making at home could be a more cost effective way to enjoy kombucha.
Kombucha is produced by fermenting tea using a "symbiotic 'colony' of bacteria and yeast" (SCOBY). Therefore, kombucha is commonly promoted as a functional beverage high in probiotics. There is some research to support this. For example, one study found that kombucha may be beneficial for fighting several pathogenic microorganisms (aka bad bacteria) (1). However, a recent study found that fermentation of tea brews with a SCOBY to make kombucha did not affect the tea’s polyphenol content and free radical fighting capacity (2). Another recent review paper highlighted the fact that many food products contain doses of probiotics that are too low to provide the benefits demonstrated in clinical trials using supplements and fortified products (3). Our conclusion is that there is a lot more research to be done before kombucha can truly be deemed a health promoting drink. For now, I consider an occasional kombucha to be a treat that may have some potential advantages over a typical sugar sweetened drink.
The recipe we tried here was actually an attempt to use up some coffee that we were not very fond of and the result was OK. We added coconut flakes and cinnamon for additional flavor.- the flavor of honey was still present in the end. Although in the future I would likely try stevia drops instead of the coconut flakes. A few other bloggers have found tricks to make the drink even more pleasurable such as doing a second ferment, using a syrup based sugar, and flavored stevia (see here). We also noted that serving the drink chilled with almond milk was pretty good too.
Follow these instructions and/or watch the video to make a batch of your own:
- Brew some coffee. We used 2 cups of whole bean coffee, ground it, and added it to 100 oz of boiled water. We have a large glass jar that can hold this much. In the future I would definitely make a smaller batch. Most sites recommend using ½ a cup of sugar and making 2 quarts.
- Let the coffee chill to room temperature
- Add in your fermentable sugar of choice and anything else you want to add that may impart additional flavor. We used 12 oz of honey, 1 cup of coconut flakes, and 1 TBSP of cinnamon.
- Add your SCOBY* Cover your jar or container with cheesecloth or a coffee filter and a rubber band.
- Ferment. We tried one week, but we did check every couple days for a few reasons: Coffee is more acidic than tea, which is thought to result in faster fermentation time and coffee has more oil than teas so we wanted to frequently check to ensure the ferment didn’t go rancid or develop off tastes.
- Remove the SCOBY, and put the kombucha in the refrigerator to prevent further fermentation. I have seen several people recommend NOT using the SCOBY used to make coffee kombucha to make tea based kombucha. In other words, only reuse it to make more coffee kombucha.
What we would to differently next time: Another blogger mentioned that second ferment is necessary to reduce the tanginess and bitterness of coffee kombucha. As noted above, we would also stick to flavor drops instead of the coconut flakes because it would be cheaper and less work. Lastly, we would make a smaller batch.
If this is your first time making kombucha, you will need to obtain a SCOBY. You could get one from friend if you know someone who makes kombucha, maybe buy from a vendor at a farmer’s market, or purchase one online. I would recommend that you buy from a reputable seller, who tests their SCOBYs. While very rare, there have been documented cases of people getting acute sickness fromkombucha making, so you want to make sure the SCOBY you are using does not contain any pathogenic microorganisms (4).
1. Sreeramulu G, Zhu Y, Knol W. Kombucha fermentation and its antimicrobial activity. Journal of agricultural and food chemistry. 2000;48(6):2589-94.
2. Gramza-Michalowska A, Kulczynski B, Xindi Y, Gumienna M. Research on the effect of culture time on the kombucha tea beverage's antiradical capacity and sensory value. Acta scientiarum polonorum. Technologia alimentaria. 2016;15(4):447-57.
3. Scourboutakos MJ, Franco-Arellano B, Murphy SA, Norsen S, Comelli EM, L'Abbe MR. Mismatch between Probiotic Benefits in Trials versus Food Products. Nutrients. 2017;9(4).
4. Greenwalt CJ, Steinkraus KH, Ledford RA. Kombucha, the fermented tea: microbiology, composition, and claimed health effects. Journal of food protection. 2000;63(7):976-81.