Over the past decade, kombucha tea has catapulted from being an obscure home brew made by fermentation fanatics, to being a darling of the American health food scene. Now available to consumers in stores ranging from Whole Foods to the grocery section of the local Target, kombucha has gained a following because of its purported health benefits. But what exactly is kombucha tea? And is it really that good for you? A number of scientists are venturing to answer this question, and their results look promising.
What is kombucha?
While the exact origins of kombucha are somewhat of a mystery, it is believed to have originated in Northeastern China around 220 B.C. It later found its way into Japan, Russia, and eastern Europe, eventually making an appearance in Germany at the start of the 20th century. From there, it wasn’t long before the Swiss, Italians, and other western Europeans began to enjoy the fizzy brew. France even introduced kombucha to French-dominated Northern Africa in the 1950s, where it remains a popular beverage to this day (Jayabalan, 2014).
Kombucha tea in its most traditional form is a fermented black tea with a delicately sweet flavor that is accented by a vinegary tang and slight fizz. It is brewed by combining black tea, sugar, some previously fermented kombucha, and a kombucha “mother” in a jar, and then allowing these ingredients to sit at room temperature for seven to twelve days (or longer if one prefers a more vinegary flavor profile). Kombucha tea is best understood by dividing the product into two main parts: the mother and the soup.
The kombucha mother, which is more formally known as a SCOBY (symbiotic community of bacteria and yeast), is actually a biofilm formed largely by yeast strains (about 80% is made up of Candida sp.), along with some bacterial strains. The SCOBY floats atop the soup, which is the liquid part of the tea that is consumed. The soup is composed of a wide variety of acetic acid bacteria (occasionally some lactic acid bacteria sneak in there, too) and yeasts, and these microorganisms are responsible for producing a number of biological compounds that are believed to impart kombucha with health benefits (Chakravorty, 2016).
Once kombucha tea has reached its optimal fermentation point (usually around day seven, but this varies with temperature), the chemical composition of kombucha includes: organic acids (most notably acetic, gluconic, glucuronic, and citric), sugars, vitamins B1, B2, B6, B12, and C, 14 amino acids, some hydrolytic enzymes, ethanol, antibiotically active matter, carbon dioxide, phenol, some polyphenols, and minerals (Jayabalan, 2014). In Part II of this series we will explore what it is about these compounds that bestows kombucha with its healing qualities.
Chakravorty, Somnath, Semantee Bhattacharya, Antonis Chatzinotas, and Writachit Chakraborty. “Kombucha Tea Fermentation: Microbial and Biochemical Dynamics.” International Journal of Food Microbiology 220 (2016): 63-72. Web.
Jayabalan, Rasu, Radomir V. Malbasa, Eva S. Loncar, Jasmina S. Vitas, and Muthuswamy Sathishkumar. “A Review on Kombucha Tea—Microbiology, Composition, Fermentation, Beneficial Effects, Toxicity, and Tea Fungus.” Comprehensive Reviews in Food Science and Food Safety 13.4 (2014): 538-50. Web.