Effect of microbial fermentation on caffeine content of tea leaves.
Wang X1, Hu S, Wan X, Pan C.
Caffeine is widely used in the food and pharmaceutical industries. For safety concerns, natural caffeine is preferred over synthetic products despite of its high cost. To explore more economical methods of acquiring natural caffeine, we adopted a microbial fermentation technique to increase the caffeine content of tea leaves. Our studies showed that the caffeine content in tea leaves increased reasonably after treating leaves with microorganisms for a period of time (i.e. orthodox pile-fermentation), and the amount of caffeine content increase varied significantly between black and green teas (27.57% and 86.41%). These results suggested that the change of caffeine content in tea leaves during the pile-fermentation depended not only on the growth and reproduction of microorganisms, but also on the tea composition.
content during the fermentation of tea with microorganisms
Kombucha is generally considered to have about ⅓ the amount of caffeine as the tea it is made with, so for example black tea, which might have 30-80mg of caffeine per cup may yield a glass of Kombucha with 10-25mg of caffeine. Green tea Kombucha might have just 2-3mg of caffeine.
Caffeine, often called America’s favorite drug, can have negative (and sometimes hilarious) effects on the body and the nervous system. Yet significant amounts of this pharmacological agent occur naturally in the 2 most popular beverages in the world (besides water), tea and coffee. Large doses are added to soft drinks and even bottled water. Like many good, naturally occurring substances found in nature, commercial production has perverted our relationship with caffeine, leaving us addicted or scared or both.
Bottle your kombucha tea when it’s slightly sweet. It will continue to ferment in the fridge. When it turns too sour, that means the yeasts and bacteria have run out of food and your kombucha will go flat. This is really important if you’re looking for fizzy kombucha. Those microbes need the sugars to consume and make probiotics and lots of carbonation. Remember, the sugar in the tea is for those good bacteria and yeasts and not for you.