Home kombucha brewing has a reputation for being either trivially easy or impossible, depending on which guide you read. The truth is closer to the easy side, with a few specific mistakes that derail beginners and a couple of details that separate flat, vinegary results from properly fizzy, balanced kombucha.
This is the guide written for someone making their first batch this week. It covers what you actually need, the basic recipe, both fermentation stages, and the troubleshooting issues that come up most often.
What you need
The equipment list is short:
- A glass jar. Half-gallon or full-gallon size, wide-mouth. Glass only, no metal or plastic for the primary fermentation. The wide mouth matters because the SCOBY grows across the surface and needs room to spread.
- A cloth cover and a rubber band. Cheesecloth folded several times, a clean tea towel, or a coffee filter. The cover keeps fruit flies out while letting the SCOBY breathe. A solid lid will not work.
- A pH strip pack or pH meter. Helpful for confirming the brew has acidified to safe levels (below pH 4.0). Optional but useful for the first few batches.
- A starter SCOBY and starter liquid. Either bought online, taken from a brewing friend, or grown from a bottle of GT’s Original kombucha. About one cup of liquid plus one SCOBY for a half-gallon batch.
- Tea bags or loose tea. Black tea is the standard. Green tea works. Flavored teas (chai, fruit-flavored, Earl Grey) can stress or kill the SCOBY because of added oils and flavorings; skip these for the primary fermentation.
- Sugar. Plain white cane sugar. Not honey (antimicrobial properties harm the SCOBY), not artificial sweeteners (the SCOBY cannot metabolize them).
- Bottles for the second fermentation. Flip-top glass bottles (Grolsch-style, EZ-Cap, similar) hold pressure and reseal easily. Avoid mason jars for second fermentation because the threaded lids do not seal well enough to build carbonation.
Total startup cost: $30 to $60, depending on whether you buy or grow the SCOBY and whether you already own a half-gallon glass jar.
The first batch: step by step
A half-gallon batch:
- Brew the sweet tea. Bring four cups of water to a boil. Add four tea bags (about eight grams of loose tea) and one cup of white sugar. Steep for ten to fifteen minutes, then remove the tea bags.
- Cool the tea. Add four more cups of cold filtered water to the hot tea. Let the mixture cool to room temperature. Hot tea will kill the SCOBY.
- Combine in the brewing jar. Pour the cooled sweet tea into your half-gallon glass jar. Add the starter liquid (about one cup) from your SCOBY package or previous batch. Place the SCOBY on top, dark side down if there is a clear orientation, otherwise either way works.
- Cover with cloth. Drape the cheesecloth or tea towel over the mouth and secure with the rubber band. Place the jar somewhere warm (70 to 78 degrees) and out of direct sunlight. The top of a kitchen cabinet works well in most homes.
- Wait. Do not move, jostle, or open the jar for the first seven days. The SCOBY needs stable conditions to establish itself.
- Start tasting at day seven. Use a clean spoon to taste a small amount each day. Initially the brew will taste sweet and tea-like. Over a few days it shifts to slightly tart, then more sour, then approaching vinegar. The right window is when the sweetness has receded but the brew has not yet crossed into harsh acidity. For most palates this is day eight to twelve.
When the taste is right, the first fermentation is done.
The second fermentation: where the bubbles come from
The brew at the end of primary fermentation is acidic, slightly sweet, and mostly flat. The fizz that most people expect from kombucha comes from a second, sealed fermentation in bottles.
The process:
- Remove the SCOBY. Use clean hands or a clean wooden spoon. Set the SCOBY aside in a small bowl with a cup of the finished kombucha. This will be your starter for the next batch.
- Add flavoring to bottles. Standard flavoring approaches: a half-inch of fresh ginger plus a tablespoon of fresh lemon juice per 16-ounce bottle, or a quarter cup of pureed berries, or a tablespoon of fresh herbs (mint, basil, lavender) plus a teaspoon of sugar.
- Fill bottles with finished kombucha. Pour the kombucha from the brewing jar into your flip-top bottles, leaving about an inch of headspace. Seal tightly.
- Ferment at room temperature, two to five days. The flavoring and remaining sugars feed the yeast, which produces CO2. The bottles will pressurize.
- Burp daily. Open each bottle briefly once per day to release excess pressure. Skip this step and you risk bottles cracking from over-pressurization. The hiss when you crack the bottle indicates how much pressure has built.
- Refrigerate when carbonation is right. Cold temperatures slow the yeast almost to a stop. Move the bottles to the fridge once the bubbles are at your preferred level.
Refrigerated bottles keep for one to two months without significant change.
Flavor ideas that actually work
The classic combinations:
- Ginger + lemon. A half-inch piece of fresh ginger plus a tablespoon of lemon juice per 16-ounce bottle. The standard kombucha flavor and the easiest first attempt.
- Berry. A quarter cup of crushed fresh or frozen berries (strawberries, blueberries, raspberries) per bottle. Produces a deeply colored, fruit-forward kombucha.
- Mango + chili. A tablespoon of mango puree plus a small pinch of chili flakes. Sweet and unusually warm.
- Lavender + honey. A teaspoon of culinary lavender plus a teaspoon of honey per bottle. The honey supports the yeast and the lavender adds a floral note.
Avoid: anything dairy (yogurt, milk products), anything oily (citrus zest with much oil, herbs high in essential oils), and anything alcoholic. These interfere with the second fermentation in different ways.
What goes wrong, and how to tell
The common failures:
Mold on the SCOBY. Fuzzy spots that are green, white, or black on the top surface of the SCOBY. This is genuine mold and the batch is dead. Discard everything including the SCOBY. Start over with a new SCOBY. Mold usually comes from contaminated equipment or from a batch that did not acidify quickly enough at the start. The fix is more starter liquid (a full cup minimum) and cleaner equipment.
Brown stringy strands hanging from the SCOBY. These are yeast strands and are normal. Not mold.
A SCOBY that sinks or grows sideways. Cosmetic only. The brew is fine.
Slow or no fermentation. The room is too cold (below 65 degrees) or the SCOBY is weak. Move the jar somewhere warmer or extend the fermentation time. If a SCOBY does nothing for three weeks, it is probably dead and needs replacement.
Vinegar taste. The first fermentation ran too long. Bottle the next batch a few days earlier.
Flat second fermentation. The brew was too acidic at the end of primary, leaving too little sugar for the yeast. Add an extra teaspoon of sugar to each bottle along with the flavoring next time, or end the primary fermentation a day or two earlier.
Over-carbonated bottles that explode. The bottles built pressure faster than expected. Burp daily during second fermentation. If you find a bottle hard to open, point it away from your face and any other people. Use a sink or a cloth to catch overflow.
The cost comparison
Bottled kombucha at the grocery store runs $3.50 to $5.00 for a 16-ounce bottle. That is roughly $7 to $10 per liter.
Home kombucha: a half-gallon batch produces about three 16-ounce bottles plus a starter for the next batch. The ingredients (tea, sugar, water) cost less than a dollar. Per bottle, home kombucha runs about 30 to 50 cents, including amortized equipment costs over a year of brewing.
For someone who drinks kombucha regularly (a few bottles a week), home brewing saves $200 to $400 per year. Combined with the ability to control flavor and carbonation level, it is one of the higher-return kitchen projects for the time invested.
Frequently asked questions
How long does it take to brew kombucha?+
The first fermentation takes seven to fourteen days at room temperature. The second fermentation (where carbonation develops and flavor is added) takes another two to five days in sealed bottles. So a complete batch from start to drinkable runs about ten days at minimum, more typically two weeks for a good first attempt. Subsequent batches are slightly faster because the SCOBY is more vigorous.
Where do I get a SCOBY to start?+
Three options: buy one online from a kombucha supply company ($15 to $25 with starter liquid), get one from a friend who brews regularly, or grow your own from a bottle of raw, unflavored, unpasteurized commercial kombucha (GT's Original is the most common starter). The grow-your-own method takes two to three weeks longer because the SCOBY has to form from scratch. The bought SCOBY is faster and more reliable for first-time brewers.
Is homemade kombucha safe to drink?+
Yes, when basic precautions are followed. The acidity of fermenting kombucha (typically pH 3.0 to 3.5) makes it inhospitable to most harmful bacteria. The risks are: improperly cleaned vessels (which can introduce mold), batches that fail to acidify enough (a brewing thermometer or pH strips catch this), and bottles that over-carbonate during the second fermentation (which can crack glass). Use food-grade glass containers, follow temperature guidelines, and burp bottles daily during second fermentation.
Why does my kombucha taste like vinegar?+
The first fermentation has gone too long. Kombucha continues to acidify the longer it sits with the SCOBY. After two weeks at warm room temperature, the sugar is largely consumed and the beverage becomes too acidic for most palates. The fix is to taste at day seven and bottle as soon as the flavor is to your preference. Most home brewers find their preferred ratio at eight to ten days during the active fermentation.
What is the difference between first and second fermentation?+
First fermentation happens in an open vessel covered with cloth, where the SCOBY converts sweet tea into sour kombucha over one to two weeks. Second fermentation happens in sealed bottles where you add flavorings (fruit, ginger, herbs) and the remaining yeast produces CO2, which builds carbonation. Both stages are necessary for the standard fizzy, flavored kombucha most people associate with the drink.
