How to Make Kombucha at Home

Kombucha—the tangy, effervescent fermented tea that has captivated health enthusiasts and culinary adventurers alike—represents one of the most accessible and rewarding home fermentation projects. As someone who maintains a library of over 30 different fermentation cultures from around the world, I’ve found that homemade kombucha consistently delivers the most impressive transformation from simple ingredients to complex final product, all while requiring minimal specialized equipment and surprisingly little hands-on time.

The art of brewing kombucha connects us to a tradition dating back thousands of years, originating in Northeast China before spreading along trade routes to Russia, Eastern Europe, and eventually worldwide. Beyond its fascinating history and purported health benefits, kombucha brewing offers a wonderful introduction to the fundamental principles of fermentation—principles that apply across countless other culinary pursuits from sourdough bread to kimchi.

In this comprehensive guide, I’ll walk you through creating your first batch of homemade kombucha, demystifying the process while highlighting the critical points that will ensure success. Whether you’re motivated by flavor exploration, potential probiotic benefits, or simply the satisfaction of crafting something uniquely your own, you’ll soon discover why kombucha brewing has become one of the most popular fermentation practices worldwide.

Understanding the Kombucha Brewing Process

At its core, kombucha brewing involves a remarkably simple process:

1. Brewing sweetened tea: Creating the nutrient base
2. Adding a SCOBY and starter liquid: Introducing the fermentation culture
3. Primary fermentation: Converting sugars to acids, carbon dioxide, and trace alcohol
4. Secondary fermentation (optional): Developing carbonation and flavor infusions
5. Bottling and storage: Preserving your finished brew

The magic happens thanks to the SCOBY (Symbiotic Culture Of Bacteria and Yeast)—a pancake-like cellulose structure housing the microorganisms responsible for fermentation. According to research from the Journal of Food Microbiology, a typical kombucha SCOBY contains primarily Acetobacter bacteria and Saccharomyces yeasts working in harmony to transform sweet tea into tangy kombucha.

Essential Ingredients for Homemade Kombucha

The Four Core Components

1. Tea: Provides the nutrient foundation and tannins
2. Sugar: Supplies food for the SCOBY’s microorganisms
3. SCOBY: Contains the culture of bacteria and yeasts
4. Starter Liquid: Creates the acidic environment needed for proper fermentation

Detailed Ingredient Breakdown

For a standard one-gallon batch:

• 3-4 tablespoons loose tea or 4-6 tea bags: Traditional black tea provides the most reliable results, though green tea also works well. Avoid flavored or herbal teas for your initial batches.
• 1 cup (200g) white granulated sugar: Regular granulated sugar works best for beginners. The SCOBY will consume most of this during fermentation.
• 1 SCOBY: Either purchased or obtained from a friend’s “SCOBY hotel”
• 1-2 cups starter liquid: This acidic liquid from a previous batch helps create the proper pH environment
• 3.5 quarts (3.3 liters) filtered water: Chlorine-free water is essential as chlorine can harm the SCOBY

According to Kombucha Brewers International, using the correct ratio of these four ingredients is more important than using premium versions of any single component.

At Brew My Beer, we recommend starting with basic ingredients before experimenting with premium teas or alternative sugar sources, as this allows you to establish a baseline for how a standard brew should progress and taste.

Equipment Needed

One of kombucha’s advantages is the minimal equipment required:

Essential Equipment

• 1-gallon glass jar (avoid metal or plastic containers)
• Breathable cover (coffee filter, tight-weave cloth, or paper towel)
• Rubber band or string to secure cover
• Large pot for brewing tea
• Long-handled spoon (wood or plastic, not metal)
• pH strips (ideal range: 2.5-3.5)
• Bottles for storing finished kombucha (flip-top bottles work well)

Optional Equipment

• Brewing thermometer
• Glass measuring cup
• Small funnel for bottling
• Fruit/vegetable juicer for flavoring
• Tiny strainer for removing solids when bottling

Step-by-Step Kombucha Brewing Process

1. Brewing the Sweet Tea Base (Day 1)

1. Boil water: Bring approximately 1 quart (946 ml) of filtered water to a boil
2. Add sugar: Remove from heat and stir in 1 cup sugar until completely dissolved
3. Steep tea: Add tea and steep according to variety (typically 3-5 minutes for black tea)
4. Cool completely: Add remaining 2.5 quarts (2.4 liters) of room-temperature water and allow to cool to below 85°F (29°C)
5. Check temperature: Verify tea is at or below 85°F (29°C) as higher temperatures can harm the SCOBY

Research from the Journal of Agriculture and Food Chemistry indicates that proper cooling is critical—high temperatures can kill beneficial microorganisms in the SCOBY, while temperatures too low can lead to sluggish fermentation or contamination.

2. Starting Primary Fermentation (Still Day 1)

1. Transfer to fermentation vessel: Pour cooled sweet tea into your glass jar
2. Add starter liquid: Add 1-2 cups of starter liquid (this creates the acidic environment needed)
3. Test pH: Ideally between 4.5-4.2 at this stage
4. Add SCOBY: Gently place your SCOBY on top of the liquid (it may float, sink, or turn sideways—all are normal)
5. Cover: Secure a breathable cover with rubber band or string
6. Label: Note the start date on your container
7. Place in fermentation location: Choose a spot with:
   
   • Stable temperature (75-85°F / 24-29°C is ideal)
   • Out of direct sunlight
   • Good air circulation
   • Minimal disturbance

3. Monitoring Primary Fermentation (Days 2-14)

1. Observe without disturbing: Watch for these signs of healthy fermentation:
   
   • New SCOBY formation at the surface
   • Increasingly tangy smell
   • Darkening of the SCOBY
   • Small bubbles rising to the surface
2. Test at 7 days: After one week, take a small sample using a clean straw:
   
   • Taste for sweetness and acidity balance
   • Check pH (should be between 2.5-3.5)
   • Continue fermenting if too sweet
3. Determine completion: Your kombucha is ready when:
   
   • The flavor balances sweetness and acidity to your preference
   • pH reads 2.5-3.5
   • Typically between 7-14 days, depending on temperature and preference

According to the International Journal of Food Microbiology, fermentation time varies significantly based on environmental factors. Warmer temperatures (80-85°F/27-29°C) can result in finished kombucha in 7 days, while cooler conditions (70-75°F/21-24°C) might require 14-21 days.

4. Secondary Fermentation (Optional, 2-5 days)

For naturally carbonated, flavored kombucha:

1. Prepare bottles: Thoroughly clean and sanitize flip-top bottles
2. Add flavoring: Place fruit, juice, or herbs in bottles (1-2 tablespoons per 16 oz bottle)
3. Fill bottles: Leave 1-inch headspace
4. Seal tightly: Close flip-top lids or screw caps firmly
5. Ferment at room temperature: 2-5 days, depending on desired carbonation
6. “Burp” bottles: Briefly open lids daily to release pressure and prevent explosion
7. Refrigerate: When desired carbonation is reached, transfer to refrigerator to slow fermentation

Popular flavoring combinations include:

• Ginger + lemon (2 tsp grated ginger, 1 tsp lemon juice per bottle)
• Blueberry + lavender (1 tbsp blueberry puree, ¼ tsp dried lavender)
• Pineapple + mint (1 tbsp pineapple juice, 2-3 fresh mint leaves)
• Hibiscus + strawberry (1 tsp dried hibiscus, 2-3 strawberries, sliced)

5. Maintaining Your SCOBY for Future Batches

1. Start a SCOBY hotel: Reserve your original SCOBY plus the new one that formed
2. Store properly: Place SCOBYs in a glass container with starter liquid
3. Cover: Use a breathable cover secured with a rubber band
4. Label and date: Keep track of your cultures
5. Feed occasionally: Add sweet tea every 4-6 weeks if not brewing regularly

Troubleshooting Common Kombucha Issues

Mold Growth

• Identification: Fuzzy patches in green, white, black, or blue (distinctly different from the cream/tan SCOBY)
• Solution: Unfortunately, you must discard everything (tea, SCOBY, and container) and start fresh
• Prevention: Ensure proper pH (below 4.5), use sufficient starter liquid, keep equipment clean

Overly Sour Taste

• Cause: Fermented too long or at too high a temperature
• Solution: Shorten fermentation time for future batches
• Salvage option: Dilute with a small amount of fresh sweet tea or fruit juice

Weak Carbonation

• Cause: Insufficient sugar for secondary fermentation or too short secondary fermentation time
• Solution: Add small amount of sugar (1 tsp per bottle) during bottling or increase secondary fermentation time

SCOBY Sinking

• Observation: Not a problem! SCOBYs may float, sink, or hover in the middle
• Solution: None needed—this is perfectly normal behavior

Health and Safety Considerations

While kombucha brewing is generally safe, consider these important points:

1. Sanitization: Clean all equipment thoroughly before use
2. pH testing: Maintain proper acidity (below 4.5 for safety, ideally 2.5-3.5 for flavor)
3. Alcohol content: Homemade kombucha typically contains 0.5-2% alcohol by volume
4. Storage: Refrigerate finished kombucha to slow continued fermentation

According to Cornell University’s Department of Food Science, maintaining proper acidity is the most critical safety factor in kombucha brewing, as an acidic environment prevents the growth of harmful bacteria.

Final Thoughts

Brewing kombucha at home connects you to an ancient tradition while providing a uniquely customizable beverage that’s impossible to replicate through commercial products. The process rewards patience and observation, teaching fundamental fermentation principles that extend to countless other culinary pursuits.

As you gain confidence with basic kombucha brewing, endless experimentation awaits—from exploring different tea varieties and sugar sources to creating sophisticated flavor combinations during secondary fermentation. Each batch becomes an opportunity to refine your technique and develop signature brews tailored precisely to your taste preferences.

Remember that fermentation is both science and art—maintain clean practices and precise measurements, but also embrace the natural variations that make each batch uniquely yours. May your SCOBYs grow healthy and your kombucha brew deliciously!