How to Make Kombucha

Kombucha is a fermented tea beverage made by adding a SCOBY (Symbiotic Culture of Bacteria and Yeast) to sweetened tea. The result is a fizzy, tangy, slightly sweet drink rich in probiotics and organic acids.

Category: Beverages · Method: Acetic Acid · Time: 7-14d · Difficulty: 2/5 · Yield: ~3L · Temp: 20-26°C

History

Kombucha originated in Northeast China around 220 BCE and was prized for its healing properties. It spread along trade routes to Russia, Eastern Europe, and eventually worldwide. The name may derive from a Japanese physician named Kombu.

Ingredients

  • 3.5 liters Water — Filtered, non-chlorinated
  • 8-10 bags or 4 tbsp loose Black or green tea — Plain tea, no oils or flavors
  • 1 cup (200g) White sugar — Regular white sugar works best
  • 1 SCOBY — With 1-2 cups starter liquid
  • 1-2 cups Starter liquid — From previous batch or store-bought raw kombucha

Equipment

  • Large glass jar (1 gallon/4 liters)
  • Breathable cloth cover
  • Rubber band
  • Wooden or plastic spoon (no metal)
  • Glass bottles for secondary fermentation
  • pH strips (optional)

Instructions

  1. Cover and ferment

    Cover jar with a breathable cloth secured by a rubber band. Place in a warm spot (20-27°C) away from direct sunlight. Ferment for 7-14 days. Ensure the environment is well-ventilated to allow the aerobic bacteria to thrive.

    Time: 7-14 days

    Tip: Avoid moving the jar during fermentation. A new SCOBY pellicle will form on top. The ideal temperature range is 20-27°C; temperatures above 30°C can stress the yeast and produce off-flavors.

  2. Taste test

    After 7 days, taste using a straw. It should be tangy but slightly sweet. For safety and consistency, use a pH meter or strips to ensure the brew has reached a pH of 2.5–3.5.

    Time: Ongoing

    Tip: A pH below 4.5 is required to prevent pathogen growth, but 2.5–3.5 is the target for the classic kombucha profile.

  3. Secondary fermentation

    Seal bottles tightly. Ferment at room temperature 2-4 days for carbonation. WARNING: Use only pressure-rated fermentation-grade glass bottles (like Grolsch-style swing tops). Non-rated glass can explode under pressure.

    Time: 2-4 days

    Tip: Burp bottles daily if using high-sugar fruits to release excess CO2. Refrigerate immediately once carbonated to stabilize pressure.

Fermentation Timeline

  • Day 1-2: SCOBY activates — Slight bubbling may appear. New SCOBY layer begins forming on surface.
  • Day 3-5: Fermentation progresses — Tea becomes cloudier. Vinegary smell develops. Sugar is being consumed.
  • Day 7: First taste test — Should have some tang. Still sweet means more time needed.
  • Day 10-14: Ready to bottle — Balanced sweet-tart flavor. Slight natural fizz.
  • Day 14-18: After 2F — Carbonated and flavored. Ready to drink!

Signs of Success & Spoilage

Good signs

  • New SCOBY forming on surface
  • Slight vinegar smell
  • Gradually increasing tartness
  • Cloudy strands (yeast) floating
  • Bubbles when disturbed

Warning signs

  • Black, green, or fuzzy mold on SCOBY
  • Strong cheese or rotten smell
  • No SCOBY growth after 3 weeks
  • Larvae or insects

Troubleshooting

Mold on SCOBY
Cause: Contamination, weak starter, or too cold Solution: Discard everything including SCOBY. Start fresh with more starter liquid.
Too sour/vinegary
Cause: Fermented too long Solution: Ferment for less time. Use as vinegar for cooking or cleaning.
No carbonation
Cause: Not enough sugar, too cold, or loose bottle caps Solution: Add a little sugar before 2F. Ensure tight seal. Ferment at warmer temp.
SCOBY sinks
Cause: Normal behavior Solution: No problem - a new SCOBY will form on the surface.

Storage

Store finished kombucha in refrigerator in sealed bottles. Keeps 1-3 months refrigerated. Store SCOBY in a SCOBY hotel (jar with sweet tea and starter) if taking a break.

Health Benefits

  • Contains probiotics for gut health
  • Rich in B vitamins
  • Contains antioxidants from tea
  • Organic acids support digestion
  • Low calorie alternative to soda
  • May support liver function

Serving Suggestions

  • Drink chilled as a refreshing beverage
  • Mix into mocktails or cocktails
  • Use as a base for smoothies
  • Salad dressing ingredient
  • Popsicles and frozen treats
  • Morning health tonic

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Authoritative food-safety sources

This site cross-references but does not replace professional guidance. For canonical, peer-reviewed fermentation safety information, consult:

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