The Ultimate Guide to What is the Ratio for Kombucha Mix

December 23, 2025 •

4 min read

According to brewing experts, the foundational ratio for a one-gallon batch of kombucha is typically 1 cup of sugar, 8 tea bags (or 2 tbsp loose tea), and 2 cups of starter tea. Understanding what is the ratio for kombucha mix is the key to creating a balanced and flavorful probiotic tea at home.

Quick Summary

Essential ratios for kombucha's first and second fermentation are crucial for a successful homebrew. Key ingredients include water, tea, sugar, and starter tea, with specific proportions affecting the final flavor and fizz. Learning proper ratios prevents mold and ensures a healthy, delicious beverage.

Key Points

First Fermentation (F1) Ratio: For a 1-gallon batch, the standard ratio is 1 cup sugar, 8 teabags, and 2 cups starter tea for every 13-14 cups of water.
Start Acidic, Stay Safe: Using enough strong starter tea (approx. 10% of the total volume) is critical to lower the pH and prevent mold growth.
F2 Flavoring is Variable: The ratio for adding flavor during the second fermentation depends on the ingredient, with guidelines of 10-30% fruit or juice to kombucha.
Sugar Feeds the Culture: The sugar added during F1 is not just for taste; it's the necessary food source for the SCOBY to ferment the tea.
Scaling is Proportional: To adjust batch size, simply scale all ingredients proportionally. For instance, a half-gallon batch requires half the amount of each ingredient from the one-gallon recipe.
Experiment Safely: While ratios provide a solid foundation, personal preference and brewing conditions can lead to minor adjustments over time for a customized flavor.
Cleanliness is Crucial: Always use clean, non-metallic equipment and filtered water to protect the SCOBY from contamination.

Mastering the Foundation: First Fermentation (F1) Ratios

The first fermentation (F1) is where the magic happens. It's the stage where your SCOBY (Symbiotic Culture of Bacteria and Yeast) consumes the sugar and nutrients from the sweetened tea, transforming it into kombucha. A balanced ratio is vital to ensure the SCOBY thrives, preventing common problems like mold growth or weak fermentation. For a standard one-gallon batch, the core ingredient ratios are generally consistent among experienced brewers.

The One-Gallon Formula

Water: Approximately 13-14 cups (or 3.5 quarts) of filtered water. Using filtered water is crucial, as chlorine and other chemicals in tap water can harm the SCOBY.
Tea: 8 teabags or 2 tablespoons of loose-leaf black or green tea. A blend is also a great option. For a richer flavor, you can increase the tea quantity slightly, but ensure it is unflavored to protect the SCOBY.
Sugar: 1 cup of granulated cane sugar. This is the food for your SCOBY. The amount of sugar might seem high, but the SCOBY will consume most of it, leaving a minimal amount in the final product.
Starter Tea: 2 cups of potent, unflavored kombucha from a previous batch or a bottle of raw, unflavored kombucha. This starter liquid lowers the pH, creating an acidic environment that protects against unwanted bacteria.

Adjusting Ratios for Different Batch Sizes

Scaling your kombucha brew is simple as long as you maintain the core proportions. The ratio is more important than the exact measurements. Here’s a quick guide for scaling up or down:

Scaling for a Smaller or Larger Batch

For a Half-Gallon Batch: Use 1/2 cup of sugar, 4 teabags (or 1 tbsp loose tea), and 1 cup of starter tea with about 6-7 cups of filtered water.
For a Two-Gallon Batch: Double the standard one-gallon recipe. Use 2 cups of sugar, 16 teabags (or 4 tbsp loose tea), and 4 cups of starter tea with approximately 7 quarts of filtered water.

Note: Always ensure the starter tea makes up about 10% of the total volume to guarantee a low enough pH at the start of fermentation.

Comparison of First Fermentation (F1) Ratios


Ingredient	One-Gallon Recipe (Standard)	Half-Gallon Recipe (Scaled Down)	Two-Gallon Recipe (Scaled Up)
Filtered Water	~13-14 cups (3.5 qts)	~6-7 cups	~7 quarts
Tea	8 tea bags (2 tbsp loose)	4 tea bags (1 tbsp loose)	16 tea bags (4 tbsp loose)
Sugar	1 cup granulated cane sugar	1/2 cup granulated cane sugar	2 cups granulated cane sugar
Starter Tea	2 cups	1 cup	4 cups

The Second Fermentation (F2): Flavor and Fizz Ratios

Once the first fermentation is complete, you can move on to the second fermentation (F2). This is where you add flavor and produce the natural carbonation. F2 ratios are less rigid than F1 and can be adjusted to personal taste. The amount of flavoring you add directly impacts the carbonation level and sweetness of your final brew.

Flavoring Ratios for F2

Fruit Juice: A common starting ratio is 10-20% juice to 80-90% plain kombucha. For a 16 oz bottle, this is about 1.5 to 3 ounces of juice. Using 1/4 cup of juice per cup of kombucha is also a popular guideline.
Fresh or Frozen Fruit: Use about 1/4 to 1/3 cup of chopped fruit per 16 oz bottle. The sugar in the fruit provides the fuel for fizz. Berries and stone fruits are excellent choices.
Herbs and Spices: These are more potent, so start with small amounts. For a 16 oz bottle, use 1/4 to 1/2 teaspoon of ground spice or a couple of sprigs of fresh herb.
Syrups: Start with 1 to 2 tablespoons of syrup per 16 oz bottle. Maple syrup, honey, and simple syrups are great options.

Understanding and Adjusting Your Mix

Brewing kombucha is part science and part art. The ratios are a guide, but your specific conditions will influence the outcome. Temperature, altitude, and the strength of your SCOBY all play a role. If your kombucha is too sweet after F1, you may need a longer fermentation period. If it's too vinegary, a shorter F1 is in order. For secondary fermentation, adjust flavoring ratios to get your desired level of sweetness and carbonation.

Signs of a Successful Ratio

F1 Success: A healthy, creamy white SCOBY forms on the surface, and the brew's smell transitions from sweet tea to a pleasant, tangy aroma.
F2 Success: After a few days, your bottled kombucha develops visible bubbles when you gently tilt it. A gentle "hiss" upon opening is a good sign of proper carbonation.

For further reading on maintaining a healthy SCOBY, see the resources provided by the American Homebrewers Association.

Conclusion

The correct ratio for kombucha mix is the cornerstone of a great homebrew. By adhering to the standard F1 guidelines for water, tea, sugar, and starter tea, and then experimenting with the F2 flavoring ratios, you can consistently produce a delicious and healthy probiotic beverage. Don't be afraid to make minor adjustments to find the perfect mix for your palate, and remember that consistent cleanliness and careful measurements are your best friends on this brewing journey.

Frequently Asked Questions

For a 1-gallon batch, the basic ratio is 1 cup sugar, 8 tea bags (or 2 tablespoons loose leaf tea), and 2 cups of starter tea, topped with filtered water.

The starter tea is crucial because it lowers the pH of the mixture, creating an acidic environment that protects the brew from mold and harmful bacteria while promoting a healthy fermentation.

Using too little sugar can starve the SCOBY, leading to a weak or moldy brew. The SCOBY consumes most of the sugar during fermentation, so it's best to stick to the recommended ratio and let the process run its course.

A good starting point for fresh fruit is about 1/4 to 1/3 cup of chopped fruit per 16 oz bottle. For juice, a 10-20% juice to 80-90% kombucha ratio is recommended.

Using too much flavoring, especially sugary fruit or juice, can lead to excessive carbonation and potentially explosive bottles. Start with smaller amounts and adjust according to your taste and desired fizz.

For a 1-liter batch, you should use at least 100 ml of strong starter tea. This maintains the critical 10% starter tea ratio for successful fermentation.

While black tea is often recommended for its robust nutrients, you can use green or a mix. However, the ratio of teabags or loose leaves generally remains the same, though you may need to steep longer for milder teas.