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Kombucha Calculator

Calculate perfect ingredient ratios for your kombucha brew

Batch Size

1 gallons

Tea Bags

8

Sugar

1 cups

Most home brewers start with 1-2 gallons

Your Recipe

1 gallons

Water

14 cups

Sugar

1 cups

Tea Bags

8

or 0.5 oz loose

Starter Liquid

2 cups

1st Fermentation7-10 days
2nd Fermentation2-4 days

Ingredient Ratios

Water14 cups
Sugar1 cups
Starter Liquid2 cups

Estimated Nutrition

Sugar per 8oz serving4.4g
Estimated Alcohol0.5-1.0%

Brewing Tips

Use Clean Equipment

Sanitize with white vinegar. Never use soap.

Temperature Matters

Keep brew at 75-85°F (24-29°C). Below 70°F risks mold.

Test Before Bottling

Taste daily after day 5. When slightly sweeter than desired, it's ready.

What You'll Need

The Kombucha Shop Organic Kombucha Starter Kit 1 Gallon

The Kombucha Shop Organic Kombucha Starter Kit 1 Gallon

$45-$604.5
View on Amazon
Urban Kitchen Kombucha Starter Kit with SCOBY & Glass Jar

Urban Kitchen Kombucha Starter Kit with SCOBY & Glass Jar

$35-$504.5
View on Amazon
Swing Top Grolsch Glass Bottles 16oz 6-Pack

Swing Top Grolsch Glass Bottles 16oz 6-Pack

$18-$254.6
View on Amazon
The Kombucha Shop Organic Kombucha Starter Kit 1 Gallon

The Kombucha Shop Organic Kombucha Starter Kit 1 Gallon

$45-$604.5
View on Amazon
Urban Kitchen Kombucha Starter Kit with SCOBY & Glass Jar

Urban Kitchen Kombucha Starter Kit with SCOBY & Glass Jar

$35-$504.5
View on Amazon
Swing Top Grolsch Glass Bottles 16oz 6-Pack

Swing Top Grolsch Glass Bottles 16oz 6-Pack

$18-$254.6
View on Amazon

As an Amazon Associate, we earn from qualifying purchases.

Example Calculations

1Beginner 1-Gallon Batch

Inputs

Batch Size1 gallon (3.8L)
Tea TypeBlack Tea
SweetnessBalanced

Result

Sugar Needed1 cup (200g)
Tea Bags8 bags
Starter Liquid2 cups (480ml)
Fermentation Time7-10 days

Perfect starter batch. Use 14 cups water, steep 8 tea bags, add 1 cup sugar. Cool to room temp, add SCOBY and starter, cover with cloth, and wait 7-10 days.

2Large 5-Gallon Batch

Inputs

Batch Size5 gallons (19L)
Tea TypeGreen Tea
SweetnessDry

Result

Sugar Needed4.25 cups (850g)
Tea Bags48 bags
Starter Liquid10 cups (2.4L)
Fermentation Time10-14 days

Large batch for experienced brewers. Use a 5+ gallon glass container, multiple SCOBYs for faster fermentation, and taste daily after day 7.

3Sweet Summer Brew

Inputs

Batch Size2 gallons (7.6L)
Tea TypeOolong Tea
SweetnessSweet

Result

Sugar Needed2.3 cups (460g)
Tea Bags18 bags
Starter Liquid4 cups (950ml)
Fermentation Time5-7 days

Shorter fermentation keeps more sweetness. Perfect base for fruit flavoring in F2. Great for those new to kombucha or who prefer milder flavors.

Frequently Asked Questions

Q

How much sugar do I need for kombucha?

Use 1 cup (200g) of sugar per gallon of kombucha. The sugar feeds the SCOBY during fermentation - most is consumed by the culture, leaving only 2-6 grams per serving in the finished brew depending on fermentation time.

  • 1 cup (200g) sugar per gallon for standard kombucha
  • Less sugar = more tart, faster fermentation
  • More sugar = sweeter start, stronger final brew
  • Most sugar is consumed during fermentation (60-80%)

White granulated sugar works best because it provides the cleanest fermentation. Raw sugar, honey, or maple syrup can be used but may produce inconsistent results and different flavors. The SCOBY converts sugar into organic acids, CO2, and trace amounts of alcohol.

Q

What is the tea to water ratio for kombucha?

Use 8 tea bags or 2 tablespoons of loose leaf tea per gallon of water. Black tea works best for beginners due to its high tannin content which the SCOBY loves, though green, white, and oolong teas also work well.

  • Always use real tea (Camellia sinensis) for best results
  • Avoid flavored teas with oils - they can harm the SCOBY
  • Herbal teas alone won't work - blend with black tea
  • Caffeine is partially consumed during fermentation
Tea TypeTea Bags/GallonFlavor ProfileSCOBY Health
Black Tea8Bold, traditionalExcellent
Green Tea10Light, grassyVery Good
Oolong Tea9Floral, complexVery Good
White Tea10Delicate, mildGood
Q

How much starter liquid do I need?

Add 1-2 cups of starter tea (mature kombucha) per gallon batch, which is 10-15% of your total volume. This acidifies the brew to pH 4.5 or lower, protecting it from mold and unwanted bacteria during the first days of fermentation.

  • 1-2 cups per gallon (10-15% of batch)
  • More starter = faster fermentation, more tart
  • Less starter = slower start, risk of mold
  • Always save 1-2 cups from each batch for next brew

Starter liquid is just as important as the SCOBY. It contains the acidic environment and beneficial bacteria needed for a healthy ferment. For your first brew, use the liquid that came with your SCOBY. Never use pasteurized store-bought kombucha as starter.

Q

How long does kombucha take to ferment?

First fermentation (F1) takes 7-14 days depending on temperature and desired sweetness. At 75-85°F (24-29°C), expect 7-10 days for balanced kombucha. Second fermentation (F2) with flavoring takes 2-4 days in sealed bottles.

  • Taste daily after day 5 to find your sweet spot
  • Warmer = faster fermentation, more sour
  • Cooler = slower fermentation, sweeter
  • F2 adds carbonation and flavor - burp bottles daily!
TemperatureF1 DurationFlavor ResultSCOBY Growth
65-70°F (18-21°C)14-21 daysMild, sweetSlow
75-80°F (24-27°C)7-10 daysBalancedNormal
80-85°F (27-29°C)5-7 daysTart, tangyFast
Q

What is a SCOBY and how do I care for it?

SCOBY stands for Symbiotic Culture of Bacteria and Yeast. It's the "mother" that ferments your tea. Keep it in a glass container with starter liquid, feed it sweet tea every 1-4 weeks, and store at room temperature. A healthy SCOBY is opaque and 1/4 to 1/2 inch thick.

  • Never use metal containers - use glass or food-safe plastic
  • Cover with breathable cloth, not airtight lid
  • SCOBY can be stored in "hotel" with starter liquid
  • Trim or discard layers if it gets too thick (>1 inch)
  • Brown stringy bits (yeast) are normal and healthy
Q

How much alcohol does kombucha contain?

Homemade kombucha typically contains 0.5-2% alcohol by volume (ABV). Longer fermentation, warmer temperatures, and more sugar produce higher alcohol content. Commercial kombucha is regulated to under 0.5% ABV. For lower alcohol, ferment shorter at cooler temperatures.

Fermentation StyleEstimated ABVFlavorFermentation Time
Sweet (short)0.3-0.5%Sweet, mild5-7 days
Balanced0.5-1.0%Sweet-tart7-10 days
Dry (long)1.0-2.0%Tart, vinegary10-14 days

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Last Updated: Mar 26, 2026

This calculator is provided for informational and educational purposes only. Results are estimates and should not be considered professional financial, medical, legal, or other advice. Always consult a qualified professional before making important decisions. UseCalcPro is not responsible for any actions taken based on calculator results.

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