Health Risks of Brewing Kombucha and How to Do It Safely
Kombucha is a fermented tea that people love not only for the taste, but also for the beneficial properties of probiotics that can promote healthier digestion. It’s so popular that many kombucha lovers take the homebrew route to brew their own. The problem, however, is that improper brewing can pose a serious food safety hazard.
Kombucha, also called mushroom tea, is a carbonated drink made from brewed black tea, sugar, and a mixed colony of live bacteria and yeast called SCOBY (Symbiotic Culture of Bacteria and Yeast). SCOBY itself is a wide variety of different bacteria and yeast, some of which we can identify and some of which we cannot, and can be bought or, if you have friends who cook kombucha, donated.
Recipes vary, but the homemade brewing process remains largely the same: The sweet blend of tea and SCOBY sits and ferments for days, sometimes weeks, in an ideal environment for any microorganism to thrive. There are several factors associated with this stage of fermentation, such as the length of the fermentation, the equipment used, etc., when things get risky and experts do not recommend preparing kombucha at home .
There are risks of getting sick, but somewhat exaggerated
Fast Microbiology 101: Friend or Foe, many microorganisms grow rapidly with moisture, nutrients (sugar, fat, and protein), temperatures of 40 to 140 degrees Fahrenheit, and pH levels of 4.5 to 10. Unfortunately, your fermenting kombucha will infect it all, so it is easier to infect it than you think. The catch-22 here is that the same environment that pathogens love is needed by friendly bacteria and yeast to work wonders for kombucha production. And on the positive side, when kombucha ferments properly, it becomes more acidic and creates an unfavorable environment for many bad guys.
However, there have been reports of serious harm associated with kombucha. In the most cited report from the Centers for Disease Control and Prevention (CDC) in 1995, kombucha consumption is linked to two diseases in Iowa. Of the two people who fell ill, one died, but a subsequent investigation by the CDC and the US Food and Drug Administration found no conclusive evidence that kombucha was the primary cause. There were virtually no signs of infection.
However, the CDC found that the surviving person fermented the kombucha much longer than usual, over 30 days, making it more acidic than usual. It turned out that these two people were also predisposed to a condition that made it difficult for their bodies to regulate their own pH. Based on these findings, the CDC determined that eating 4 ounces of kombucha a day would be fine for healthy people, and recommended avoiding excessive fermentation (7-10 days seems to be the normal limit) if you boil it yourself at home. , just in case. Since that 1995 report, several case studies related to regular consumption of kombucha have also been linked tolead poisoning , liver damage, cutaneous anthrax, and metabolic acidosis.
Yes, there is a small but real danger when preparing your own kombucha, but it’s like cooking and handling raw meat or canned food when unsanitary conditions and negligence are more likely to infect your food with harmful pathogens. Just don’t be sloppy.
How to safely boil kombucha at home
Food safety starts with sanitation. Many problems can be solved in the bud with sterile equipment, a clean place, and a healthy SCOBY that you get from a trusted commercial source. If you would rather use a SCOBY donated by your friend, make sure your friend knows what they are doing. Double check their performance, making sure the SCOBY is free of black spots or other signs of mold or dirt.
Since you don’t want to kill your kombucha mates, avoid using bleach and any antibacterial soap. Instead, you can clean and submerge all of your equipment and vessels in over 160 degrees water for 30 seconds or more . Oh, and don’t forget to wash your hands too. Obviously. In addition to following the instructions, keep the following in mind:
- Brew tea in very hot water: Use hot water that is over 165 degrees Fahrenheit to brew the tea.
- Use Glass Containers: The CDC recommends avoiding preparing or storing kombucha in ceramic or lead containers as the acidity of kombucha tea can leach toxic chemicals into the tea itself.
- Don’t skimp on sugar: White sugar is food for bacteria in your SCOBY, but sufficient amounts also help lower the pH level to minimize the chances of other bacteria growing during the fermentation process. Some people report great results from honey, agave, maple syrup, and other alternative sweeteners , but sweeteners like molasses may not produce enough acetic acid-producing bacteria and give you less than desired results.
- Be careful with too long fermentation : the typical fermentation period is 7-10 days, but some people take up to 30 days. The longer it ferments, the more acidic and less sweet it becomes, which can be problematic for people who are sensitive to over-acidic foods. Another thing is that usually the alcohol content is below 1%, but it can reach 3% after a really long fermentation.
As noted in this Journal of Environmental Health report , kombucha is most likely to become contaminated during fermentation . There are a few precautions you can take to minimize the chances of infection: Keep Kombucha in an open, warm place (ideally around 70 degrees) with good air circulation, such as the top of your refrigerator or kitchen counter, to keep out of direct sunlight. away from other objects such as plants to avoid cross-contamination. Then check that the pH of your kombucha has dropped below 4.2 after seven days using such pH test strips .
If not, the culture is likely contaminated or the kombucha is not fermenting enough in a warm enough environment. In any case, if your kombucha looks or tests incorrectly, discard the current batch and start a new one. Don’t try to save the one you have.
At first, you may mistake signs such as brown fibrous pieces, white spots on the surface of the liquid and the formation of a “baby SCOBY” for contaminated kombucha, but this is actually normal. Keep an eye on your SCOBY and check it periodically for mold or other wild bacteria. Mold, which can ruin a batch of kombucha, is just like a good loaf of bread, and it usually looks like green or black floating pieces on the surface of the kombucha. Here’s an example of what moldy kombucha looks like . If you’re skeptical, throw it away and start over. It’s not worth the risk.
Test your kombucha with pH test strips, which should show a pH between 2.6 and 4.2 . An alternative and risky way is to taste kombucha by scooping up some liquid through a straw. Kombucha shouldn’t smell like a cheesy or rotting smell. It should have a vinegar flavor and aroma.
There is little evidence to support the wild health claims that kombucha fans are touting about their favorite drink, but even if you don’t believe them, the drink is delicious and easy to make at home. If you’re going to cook this, do it carefully, because homemade kombucha can go bad if you’re not careful. At best, socks will taste after the gym. In the worst case, you can become seriously ill.