How to make it
How to brew kombucha at home with a tested, safe recipe
Sweet tea fermented by a SCOBY. A university-tested recipe now exists, with clear safety steps. The health claims are almost entirely untested in people, and home kombucha is not for everyone.
By the editors of Alimentotherapy Last reviewed 6 min read Not medical advice
- Makes
- About 1 gallon (27 to 34 four-ounce servings)
- Hands-on
- 45 minutes
- Total time
- 7 to 10 days
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The short answer
Brew 1 gallon of sweetened black and green tea, cool it below 95°F, add a SCOBY with starter liquid of pH 4.0 or less, and ferment under a cloth at 68 to 77°F for 7 to 10 days, then bottle, refrigerate and drink within 30 days, per the National Center for Home Food Preservation’s tested recipe Nchfp. There is almost no human evidence for any health effect: a 2019 systematic review found a single human study Kapp 2019, and our fermented foods page grades kombucha not supported.
Ingredients and method
Ingredients
- 1 gallon water, divided (4 cups heated, 12 cups cold)
- 3 tablespoons loose black tea (or 6 tea bags)
- 1/3 cup plus 2 tablespoons loose green tea (or 13 tea bags)
- 1 cup granulated sugar
- 1 SCOBY with its starter liquid
Equipment
- 1-gallon glass fermentation jar (not glazed earthenware or ceramic)
- Large pot for heating water
- Food thermometer
- pH test strips or litmus paper
- Paper towel, coffee filter or clean cheesecloth, and a rubber band or string
- Clean glass jars or bottles for storage
- Basin of hot water (at least 171°F) for sanitizing
Clean and sanitize
Clean the kitchen area and wash your hands with soap and water for at least 20 seconds. Wash and rinse all equipment, then sanitize it by submerging in hot water of at least 171°F for at least 30 seconds.
Test the starter liquid
Put 1 tablespoon of the starter liquid in a small cup and test it with a pH strip, then discard that tablespoon. If the pH is 4.0 or less, go on. If it is above 4.0, do not use it: get fresh starter liquid.
Steep the tea
Heat 4 cups of water to 160 to 170°F, checked with a thermometer, add the black and green tea and steep for 2 minutes. Remove the bags or strain out the leaves.
Sweeten and cool
Pour the tea into the fermentation jar, add the sugar and stir to dissolve. Add the 12 cups of cold water and stir. Check the temperature: it must be below 95°F before the culture goes in.
Add the SCOBY
Add the SCOBY and its starter liquid and stir well for 10 seconds. Dry the jar opening, cover with a paper towel, coffee filter or clean cheesecloth, and secure it with a rubber band or string.
Ferment 7 to 10 days
Label the jar with the date (day 0). Leave it at room temperature, 68 to 77°F, for 7 to 10 days, out of direct sun.
Bottle and refrigerate
Pour the finished kombucha into clean, sanitized jars or bottles and refrigerate promptly. Use within 30 days. Keep back the SCOBY and some liquid for the next batch.
Flavor after, not during
Add fruit, ginger or herbs only after fermentation, then drink it right away or refrigerate and use within 2 days. Sealed bottles build up carbon dioxide and can burst: check them and open carefully.
If you need the equipment
Why use this recipe and not a blog version
For years there was no tested home kombucha recipe in the US. The one above is from the National Center for Home Food Preservation, whose safety factors (sanitizing at 171°F, a starter pH of 4.0 or less, cooling below 95°F, 7 to 10 days at 68 to 77°F, refrigerated use within 30 days) came from microbial survival research by the University of Georgia and Kansas State University Nchfp. Follow it as written, including the amounts of tea and sugar: the sugar feeds the fermentation that makes the brew acidic.
University of Georgia Extension explains the chemistry. Yeasts in the SCOBY turn sugar into alcohol, and acetic acid bacteria turn that alcohol into acetic acid, so the drink grows more acidic as it ferments, and that acidity helps hold back harmful bacteria Uga.
What can go wrong
Mold. If the brew does not get acidic enough, mold can grow. UGA describes the sign as dry, fuzzy patches, white or colored, on the SCOBY or the liquid surface; discard both and sanitize the containerUga.
Lead from ceramic. Kombucha is acidic enough to pull metals out of glazes. UGA warns against fermenting or storing it in glazed earthenware Uga, and doctors in Australia reported a married couple who needed chelation therapy for lead poisoning after six months of drinking kombucha brewed in a ceramic potPhan 1998.
Unexplained illness. In 1995 the CDC investigated severe illness, including one death, in two people in Iowa who had drunk kombucha daily for about two months. The report described the illness as possibly associated with kombucha, and Iowa health officials advised people not to drink it until its role was evaluated CDC 1995.
Safety
UGA Extension says up to 4 fluid ounces a day appears safe for most healthy people, but advises against kombucha for people with a weakened immune system, a tendency to acidosis, or who are pregnant or breastfeeding, because the risks are unknown. Alcohol can also exceed the 0.5 percent limit for nonalcoholic drinks, so anyone avoiding alcohol should skip it Uga.
Does kombucha do anything for health?
The claims run far ahead of the research. When Kapp and Sumner searched three databases in 2018 and reviewed 310 articles, they found one study reporting human results, and no registered clinical trials Kapp 2019. Lab and animal findings do not tell you what a glass does for a person. That is why our fermented foods page grades kombucha not supported, while fermented foods in general get a limited grade from one small diet trial.
Brew it if you enjoy the taste and the process. If you want a ferment with better human evidence, milk kefir has trial data for lactose digestion: compare them on kombucha vs kefir.
Getting a SCOBY
You need a live culture and enough acidic starter liquid to pass the pH 4.0 test. A friend who brews can spare one, or you can buy one. Bottled kombucha, sold in supermarkets and on iHerb, lets you taste it before committing to a gallon a week.
Food safety
- Do not start a batch with starter liquid above pH 4.0; acidity is what holds back harmful bacteria.
- Brew and store only in glass or food-grade containers, never glazed earthenware or ceramic: acidic kombucha can leach lead from glazes.
- Discard the tea and the SCOBY if you see dry, fuzzy patches of white or colored mold on the SCOBY or the surface, then clean and sanitize the jar.
- Airtight bottles can build pressure and explode; refrigerate promptly and check them.
- Home kombucha can contain alcohol. Skip it if you are pregnant or breastfeeding, have a weakened immune system or are prone to acidosis, and do not give it to children.
- UGA Extension suggests up to 4 fluid ounces a day for most healthy people.
Common questions
How long does homemade kombucha take to ferment?
7 to 10 days at room temperature, 68 to 77 degrees F, in the National Center for Home Food Preservation's tested recipe. Then bottle it, refrigerate it promptly and use it within 30 days.
Is homemade kombucha safe?
It can be when you follow a tested recipe: sanitize equipment, use starter liquid of pH 4.0 or less, brew in glass, and discard any batch with fuzzy mold. UGA Extension advises against it in pregnancy, while breastfeeding, and for people with weakened immune systems.
Does kombucha have proven health benefits?
No. A 2019 systematic review of 310 articles found only one study reporting results in human subjects. Most health claims for kombucha come from lab and animal work.
Sources
Primary research and government sources, each checked on the date this page was reviewed.
- GuidelineNational Center for Home Food Preservation (University of Georgia). Kombucha Tea.
- GuidelineCullinan S, et al. What's the Word on Homemade Kombucha? University of Georgia Extension Circular 1312. 2024, revised 2026.
- PubMedKapp JM, Sumner W. Kombucha: a systematic review of the empirical evidence of human health benefit. Ann Epidemiol. 2019. PMID 30527803.
- PubMedPhan TG, et al. Lead poisoning from drinking Kombucha tea brewed in a ceramic pot. Med J Aust. 1998. PMID 9887919.
- PubMedCenters for Disease Control and Prevention. Unexplained severe illness possibly associated with consumption of Kombucha tea, Iowa, 1995. MMWR. 1995. PMID 7476846.
Keep reading
- RemedyFermented foodsSauerkraut, kimchi, miso, kefir and kombucha. One well-run trial suggests eating more of them changes the gut microbiome; claims beyond that are mostly untested in people.
- Kitchen practiceFermentationThe oldest way to keep vegetables through winter. A tested method, the right salt and clean equipment make it safe; the health claims are more modest than the hype.
- ComparisonKombucha vs kefirBoth are fizzy fermented drinks, but they start from different things: kombucha from sweet tea, kefir from milk (or sugar water for water kefir). Kefir has a little human evidence; kombucha has nearly none.
- How to make itWater kefirA lightly fizzy, sour-sweet drink made by fermenting sugar water and a dried fig with water kefir grains. No extension service has tested a home recipe yet, so this one uses the conditions reported in research.
- GoalFood and the gut microbiome: fiber, fermented foods and probioticsMicrobiome science is young. A varied, fiber-rich diet is sensible on many grounds, one small trial found fermented foods raised microbe diversity, and probiotic evidence is strain- and condition-specific.