How to Brew Kombucha at Home: Complete Beginner's Guide

Kombucha is a fermented tea drink that has been enjoyed for centuries. It is made by adding a symbiotic culture of bacteria and yeast (SCOBY) to sweetened tea, then allowing the mixture to ferment for 7 to 14 days. During fermentation, the SCOBY consumes most of the sugar and produces organic acids, B vitamins, enzymes, and a small amount of alcohol (typically under 0.5%).

The result is a slightly tart, effervescent drink with a complex flavor profile that can range from mildly sweet to pleasantly vinegary. Many people drink kombucha for its taste, while others appreciate the probiotics and organic acids it contains. Either way, brewing your own at home is surprisingly simple, costs a fraction of store-bought bottles, and lets you control the flavor, sweetness, and carbonation exactly to your liking.

Before you start, gather the following equipment and ingredients. You probably already have most of these in your kitchen.

Equipment:

• A large glass jar (1 gallon / 3.8 liters is ideal for beginners)
• A tightly woven cloth or coffee filter and a rubber band (to cover the jar)
• A pot for boiling water
• Flip-top glass bottles for second fermentation (we recommend 16 oz / 500 ml swing-top bottles)
• A pH meter or pH strips (optional but recommended)
• A thermometer

Ingredients:

• Tea: 4-6 bags of black or green tea (or 2 tablespoons loose leaf). Avoid herbal teas for your first brew — they lack the nutrients the SCOBY needs.
• Sugar: 1 cup (200g) of plain white sugar per gallon. The SCOBY eats this, so do not substitute with artificial sweeteners.
• Water: 3.5 liters of filtered or dechlorinated water. Chlorine can harm your SCOBY.
• SCOBY: One healthy SCOBY with at least 1 cup (240 ml) of starter tea (mature kombucha from a previous batch or from the SCOBY seller).

Use our Tea-to-Water Ratio Calculator and Sugar Ratio Calculator to dial in exact amounts for your brew volume.

Bring about 1 liter of water to a boil in a large pot. Remove from heat and add your tea bags or loose leaf tea. Steep for 5 to 7 minutes — a bit longer than you would for drinking tea, since the tannins help the SCOBY thrive.

Remove the tea bags (or strain out loose leaf) and stir in the sugar while the tea is still hot. Stir until completely dissolved. Then add the remaining cold water to bring the total volume to about 3.5 liters. This cools the tea down faster.

Pro tip: Never add your SCOBY to hot tea. The culture is alive and temperatures above 35°C (95°F) will damage or kill the bacteria and yeast. Wait until the tea is at room temperature — ideally between 20°C and 25°C (68°F to 77°F) — before proceeding.

Once the sweet tea has cooled to room temperature, pour it into your clean glass jar. Add the starter tea (the mature kombucha that came with your SCOBY). The starter tea is critical because it acidifies the brew immediately, lowering the pH to around 4.0-4.5 and creating an environment that prevents mold and harmful bacteria from growing.

Gently place your SCOBY on top of the liquid. It may float, sink, or hover sideways — all of these are normal. A new SCOBY will form on the surface regardless of where the mother SCOBY sits.

Cover the jar with a tightly woven cloth or coffee filter secured by a rubber band. The cover needs to keep fruit flies and dust out while still allowing airflow. Never use a solid lid — the fermentation process produces carbon dioxide that needs to escape.

If you have a pH meter, check the pH at this point. It should be between 4.0 and 4.5. If it is above 4.5, add a splash more starter tea or a tablespoon of distilled white vinegar.

Place your jar in a warm spot out of direct sunlight. The ideal temperature range for first fermentation is 22°C to 28°C (72°F to 82°F). At these temperatures, fermentation is steady and balanced. Below 20°C, fermentation slows dramatically and mold risk increases. Above 30°C, the brew becomes vinegary very quickly.

Now, wait. First fermentation typically takes 7 to 14 days, depending on temperature, the strength of your SCOBY, and your taste preference. During this time, you will notice several things:

• Days 1-3: Small bubbles appear. A thin film may start forming on the surface — this is the new SCOBY beginning to grow.
• Days 4-7: The new SCOBY thickens. The tea becomes less sweet and more tart. Brown yeast strands hanging from the SCOBY are completely normal.
• Days 7-14: The kombucha becomes increasingly acidic. The flavor shifts from sweet tea to a balanced sweet-tart drink.

Do not move, shake, or disturb the jar during F1. The new SCOBY forming on the surface is fragile in its early days.

Starting around day 7, taste your kombucha daily using a clean straw or by carefully pouring a small amount. You are looking for a balance between sweetness and tartness that you enjoy. If it is too sweet, let it ferment longer. If it is too tart, bottle it sooner next time.

Check the pH if you have a meter. Kombucha is ready when the pH is between 2.5 and 3.5. At pH 3.0, most people find a pleasant balance. Never drink kombucha with a pH above 4.0 — it has not fermented long enough to be safe.

The amount of sugar remaining in the finished kombucha depends on how long you ferment. A 7-day brew retains more sugar and sweetness, while a 14-day brew is more tart and has less residual sugar. Neither is wrong — it comes down to personal preference.

Use our pH Guide Calculator to interpret your readings and know exactly when your brew is ready.

Second fermentation is where you add carbonation and flavor. It is optional but highly recommended — this is what transforms flat, plain kombucha into the fizzy, flavorful drink you know from the store.

Remove your SCOBY and 1-2 cups of kombucha (this becomes your starter tea for the next batch). Pour the remaining kombucha into flip-top bottles, leaving about 2 inches of headspace. Add your chosen flavorings:

• Fruit: 1-2 tablespoons of chopped fresh fruit or 1 tablespoon of fruit juice per 500 ml bottle
• Ginger: 1 teaspoon of freshly grated ginger per bottle
• Herbs: A few fresh mint or basil leaves
• Juice: 10-15% juice by volume (about 50 ml per 500 ml bottle)

Seal the bottles tightly and leave them at room temperature for 2 to 4 days. The remaining yeast and bacteria consume the added sugars and produce carbon dioxide, which, trapped in the sealed bottle, carbonates the drink. Check our detailed Second Fermentation Guide for more flavor combinations and advanced techniques.

After 2-4 days of F2, move your bottles to the refrigerator. Cold temperatures halt fermentation and stabilize the carbonation. Let the bottles chill for at least 4 hours before opening.

Opening tip: Always open kombucha bottles over a sink or bowl, especially in your first few batches while you learn how much carbonation your process produces. Open the cap slowly, releasing pressure gradually. If you hear aggressive hissing, close the cap, wait a moment, and try again.

Your homemade kombucha will keep in the refrigerator for 2 to 3 months, though the flavor will continue to develop slowly. Most people find it tastes best within the first 2-4 weeks.

Before you finish every bottle, remember to save your SCOBY and 1-2 cups of strong starter tea for your next batch. With each brew, your SCOBY grows a new layer, and over time you will build up a healthy SCOBY hotel for backup cultures. Read our SCOBY Care Guide for everything you need to know about maintaining your cultures.

Every new brewer makes mistakes. Here are the most common ones and how to avoid them:

• Using antibacterial soap on equipment: Residue can kill your SCOBY. Rinse everything thoroughly with hot water, or use white vinegar as a natural sanitizer.
• Not enough starter tea: Always use at least 1 cup (240 ml) per gallon. Too little starter tea means the pH stays too high, inviting mold.
• Metal contact: Avoid prolonged contact between kombucha and metal (except stainless steel). The acid in kombucha can react with metals and harm the culture.
• Flavored or oily teas: Earl Grey (contains bergamot oil) and heavily flavored teas can inhibit SCOBY growth. Stick to plain black, green, or white tea for F1.
• Skipping the cloth cover: Without a breathable cover, CO2 builds up and fermentation suffers. Worse, fruit flies can lay eggs in open containers.
• Fermenting too cold: Below 18°C (65°F), fermentation nearly stops and mold risk increases significantly. Use a heating mat if your home is cool.
• Panicking about yeast strands: Brown, stringy bits hanging from the SCOBY are harmless yeast. They are a sign of healthy fermentation.

How long does it take to brew kombucha?

First fermentation takes 7-14 days. Second fermentation takes 2-4 days. Total time from start to drinking is about 10-18 days.

Is homemade kombucha safe?

Yes, when brewed correctly. The low pH (below 3.5) makes it inhospitable to harmful bacteria. Always use enough starter tea and check your pH. If you see fuzzy mold (white, green, or black — fuzzy and dry, on top of the liquid), discard the entire batch and SCOBY.

How much alcohol does kombucha contain?

Homemade kombucha typically contains 0.5% to 2% alcohol. Longer fermentation and warmer temperatures tend to produce slightly more alcohol. This is comparable to or less than a light beer.

Can I use honey instead of sugar?

Raw honey has antimicrobial properties that can harm your SCOBY. If you want to use honey, use pasteurized honey and be aware that it creates a different culture called "jun." For your first few batches, stick with plain white sugar.

My SCOBY sank — is it dead?

No! A SCOBY sinking is perfectly normal. A new SCOBY will form on the surface. The position of the mother SCOBY has no effect on fermentation quality.

Can I take a break from brewing?

Yes. Place your SCOBY in a jar with plenty of mature kombucha (a SCOBY hotel), cover it, and store it at room temperature. It can survive for weeks or even months. Feed it fresh sweet tea every 4-6 weeks to keep it healthy.