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The Perfect Kombucha Ratios for Any Size Brew

Kombucha Ratio

After you’ve home brewed kombucha for the first time, it's a pretty easy process to repeat. However, the problem I had almost every time I started a new brew was remembering the correct ingredient ratios.

There are tons of kombucha recipes out there, but very few that give an adjustable ratio so that you can brew the amount of kombucha you want. So I decided to make one myself.

For a 1 gallon (16 cups) brew of kombucha, the typical ingredient ratio is 1 cup of sugar, 8 tea bags or 2 tablespoons of loose leaf tea, and 2 cups of starter tea.

If you are not brewing by the gallon and want to brew to the cup, to make 1 cup of kombucha you need: 0.0625 cups of sugar, 0.5 tea bags or 0.375 teaspoons of loose leaf tea, and 0.125 cups of starter tea. Just multiply these numbers by the number of cups of kombucha you want to brew and you’ll have the correct amount of ingredients. 

Quick Kombucha Ratios

To get you brewing kombucha as quickly as possible, here are the ingredient ratios adjusted to different size brews.

To make 1 Cup of Kombucha (Multiply each # by # of cups needed)

0.0625 Cups of Sugar

0.5 Tea Bags or 0.375 Teaspoons of Loose Leaf Tea

0.125 Cups of Starter Tea

To Make a ½ Gallon of Kombucha (8 Cups)

½ Cup of Sugar

4 Tea bags or 1 Tablespoon of Loose Leaf Tea

1 Cup of Starter Tea

To Make 1 Gallon of Kombucha(16 Cups)

1 Cup of Sugar

8 Tea Bags or 2 Tablespoons of Loose Leaf Tea 

2 Cups Starter Tea 

To Make 1 ½ Gallons of Kombucha (24 Cups)

1 ½ Cups of Sugar

12 Tea Bags or 3 Tablespoons of Loose Leaf Tea

3 Cups Starter Tea

To Make 2 Gallons of Kombucha (32 Cups)

2 Cups of Sugar

16 Tea bags or 4 Tablespoons of Loose Leaf Tea

4 Cups of Starter Tea

If your an experienced kombucha brewer, these quick ratios should be enough to get you brewing. But if you’re a new kombucha home brewer unfamiliar with the process, what these ratios mean, and why these ingredients are used, this article will walk you through it all. Let's start with the basics.

Why You Should Home Brew Kombucha

Home brewing kombucha is a hobby that many kombucha drinkers, including myself, really enjoy.

There are tons of advantages to brewing your own booch. For one, store bought kombucha is really expensive, usually costing around $4 a bottle. When you brew your own booch, you can make gallons of it for super cheap. 

Brewing your own kombucha also allows you to create your kombucha exactly how you want it, experiment with new flavors, and it's super fun and easy!

I’ve been brewing my own kombucha for a little over 2 years now and had so much fun that I started an entire website about it! 

How Kombucha is Made

So how do home-brewers make kombucha? Well to describe the process quickly, all booch begins as sweet tea. What turns this sweet tea into sweet and sour probiotic kombucha is a living culture of bacteria. This culture of bacteria, known as a SCOBY (Symbiotic Culture of Bacteria and Yeast), eats the sugar and caffeine from the sweet tea and produces acids, carbon dioxide, and alcohol.

Once it has eaten enough sugar to make the kombucha bitter tasting, the SCOBY is removed and the 1st fermentation is complete. At this point the kombucha can be drunk, but it's not carbonated or flavored yet.

The carbonation and flavor is added in a 2nd fermentation. During this stage, the kombucha is sealed in glass fermenting bottles that are filled with fruit, juice, or herbs for flavoring. 

Over the course of a few days, the kombucha in the bottles develops carbonation and flavor. It’s then refrigerated and ready to be drunk!

Why You Need the Correct Ratio of Ingredients to Brew Kombucha

Because kombucha is full of a living culture of bacteria (the SCOBY), it is really important that we make it with the correct amount of every ingredient. If we put too little or too much of an ingredient, we not only ruin the batch we are making, but possibly cause mold to develop or hurt our SCOBY.

The 3 ingredients you need understand in order to start making kombucha are sugar, tea, and starter tea.


Sugar is vital to the process of brewing kombucha because it is the SCOBY’s food.

The SCOBY eats the sugar and then processes it into alcohol, acids, and carbon dioxide. The longer our brew ferments, the more sugar the SCOBY and the more bitter the brew becomes.

Like most living things, if the bacteria culture doesn’t have enough food (sugar) it will die from starvation. Your brew can also become moldy if it doesn't have enough sugar, because the alcohol and acids that the SCOBY produces keep the acidity of the brew high, and a high acidity prevents mold development.

So if the SCOBY doesn’t have enough sugar, it won't produce enough acids and the brew will become vulnerable to mold growth. And if your brew gets moldy, you’ll have to throw it away.

If you want to learn more about SCOBY mold and how you can prevent it check out my article "What SCOBY Mold Looks Like and How to Prevent it" here.


Tea is important in brewing kombucha because it has key nutrients that the SCOBY needs to survive.

Whether the tea you use to brew kombucha is black, green, white, oolong, or a combination of them isn't super important. What is important is that the tea you use is caffeinated, organic, and pure.


It turns out that the first time tea leaves are washed is when you brew them! This means that if the tea you use isn’t organic, pesticides and chemicals are likely going to end up in your kombucha.

Even if you’re not worried about consuming these chemicals yourself, you should be worried for your SCOBY. Because the SCOBY eats basically whatever you give it, if there are chemicals and pesticides in your tea, it’s going to eat these things.

And because of how sensitive the SCOBY is, (even touching it with unwashed hands could damage it) if you give it something it’s not supposed to eat such as pesticides or chemicals, it’s going to get either killed, or weakened to the point where it can’t fight off mold growth.

Inorganic tea can work to make kombucha, but ideally, the tea you use to brew kombucha is organic.


The reason to use pure tea leaves to brew kombucha is that they will give you the cleanest flavor and most nutrients possible out of the tea. These extra nutrients are not only good for you, but will also be great for keeping the SCOBY healthy.

Another reason to use pure tea is that the chemicals in scented or flavored teas can hurt the SCOBY, leading to your kombucha tasting funny, the SCOBY dying, or your brew becoming moldy.


While organic and pure tea leaves will make better and healthier kombucha, they are optional. What’s not optional is that the tea you use to brew kombucha NEEDS to be caffeinated. Caffeinated tea is necessary because caffeine is one of the most important nutrients for keeping the SCOBY healthy.

Because the bacteria culture eats a lot of the caffeine during the brewing process, your finished kombucha will likely have no more than 15mg of caffeine (a cup of coffee has 95mg). But, if you want to further reduce the amount of caffeine in your booch, there are a few tweaks you can make to the brewing process. 

  • Using green tea instead of black will reduce the amount of caffeine in your brew since green tea usually has less caffeine.

  • Brewing your kombucha longer will give the SCOBY more time to eat the caffeine, reducing the amount in the finished brew.

  • If you do choose to brew with decaffeinated tea, I recommend brewing in a separate container than normal and not with your main SCOBY, since the SCOBY will likely become weak and damaged from it over time.

Starter Tea

Starter tea is just leftover kombucha from our last brew that we use to kickstart the beginning of a new brew.

When you first start brewing kombucha, a SCOBY bought online will come packaged in starter tea. But once you are brewing regularly, you’ll need to set a few cups of kombucha aside after every brew to use as starter tea for the next.

The purpose of starter tea is to prevent mold during the early stages of fermentation when little acidity has been created and the kombucha is most vulnerable to mold growth.

If you forget to save some starter tea from your last batch, you can use distilled white vinegar or a bottle of store bought, unflavored raw kombucha instead.

DO NOT however, use apple cider vinegar as starter tea. Apple cider vinegar is unpasteurized, meaning it has its own culture of bacteria that will negatively interact with SCOBY and ruin our kombucha.

Final Thoughts

Having the correct kombucha ingredient ratios will allow you to brew kombucha correctly in whatever quantity you want. As a kombucha home-brewer myself, they've really come in handy when starting a new brew, so feel free to screenshot or save this article and hang it up in your kitchen to use for future brews.

And if you want to learn more about kombucha, how it relates to your health, and even how to brew it yourself, check out the rest of my website! 

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