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A Simple Healthy and Tasty Keto kombucha Recipe

Whether you have been home brewing kombucha for a while and just started the keto diet, or you have been keto dieting for a while and just started home brewing kombucha, there are many people out there that want to make kombucha in a way that it will keep them in ketosis

So how do you make keto kombucha?

To make keto kombucha, brew kombucha like normal but only use ¾ cup of sugar per gallon, ferment for a longer time, and use no sugar flavorings like herbs, flowers, or artificial sweeteners. The final sugar content of kombucha can be measured using a hydrometer, and the drink can be diluted with water if it’s still too sweet.

Below I’m going to walk you through my simple, healthy and tasty keto kombucha recipe. Making your kombucha keto really isn’t a tough task, and at the end of this article you’ll be able to do it! Let’s get started!

What Makes Keto Kombucha Different from Regular Kombucha?

All properly made kombucha has some amount of sugar in it. This is because sugar is an essential ingredient used by the living bacteria and yeast culture to ferment kombucha.

This culture, called the SCOBY (Symbiotic Culture of Bacteria and Yeast) uses the sugar as food and turns it into the alcohol, acids, and carbon dioxide, creating kombucha.

The only thing that makes our home brewed kombucha “keto” is our effort to reduce the amount of sugar in the final kombucha as much as possible. So that hopefully in the end our bottles of homemade kombucha only have a few grams of sugar in them and will comfortably fit into your allotted carbohydrates for the day.

So then obviously the big question is what things influence the amount of sugar in finished kombucha? and what can we do to reduce it as much as possible?

How to Reduce the Amount of Sugar in Kombucha as Much as Possible

Let’s talk about some of the things that will affect how much sugar is in your kombucha, and how you can tweak them to make your kombucha keto.

1. Use Less Sugar

As I said earlier, all kombucha needs to have sugar in it because without sugar, the bacteria and yeast culture has no fuel to do fermentation.

The general rule in home brewing is to use 1 cup of sugar per gallon of kombucha. The finished kombucha won’t have this much sugar in it since most of it will be eaten by the SCOBY, but some will be left over.

It’s important that you use enough sugar so that the living SCOBY has enough food to stay healthy and fight off mold. However, if you’re trying to create a low sugar, keto kombucha you might be able to get away with only using ¾ cup of sugar per gallon of kombucha.

Only using ¾ cup of sugar per gallon should lower the final sugar content a little bit, but it's probably the least amount of sugar you should ever use. Since if you go any lower your SCOBY may not have enough food to stay healthy.

2. Use a Longer 1st fermentation

The 1st fermentation of kombucha is a 1-2 week period when the SCOBY sits in the sweet tea that kombucha starts as, and ferments the sugar to create kombucha.

At the end of the 1-2 weeks, enough of the sugar should have been eaten to give the kombucha its signature bitter and vinegary taste, but there’s still some sugar leftover to keep it sweet.

The longer the booch ferments, the more time there is for the SCOBY to eat the sugar. So if you want less sugar in your kombucha, giving it a few extra days of fermentation could help.

The trick is not letting the kombucha ferment too long or else it will get too vinegary tasting and become undrinkable.

If you’re trying to ferment your brew as long as possible to lower the sugar content, while still retaining a hint of sweetness for taste I recommend taste testing the brew at least once a day to prevent it from fermenting too long and becoming undrinkable.

3. Use a No Sugar Flavoring or Artificial Sweeteners

Technically we could make a kombucha with zero sugar if we just fermented it for long time and turned it into vinegar. But no one wants to drink vinegar, and a big part of why people drink kombucha at all is because it has some level of sweetness to it that balances out the more harsh, sour flavors.

So how do you get some sweetness in your keto kombucha without adding sugar and carbohydrates? By using no sugar flavorings or artificial sweeteners like monk fruit, allulose or erythritol.

Some good no to low sugar flavorings you can use are herbs, roots, and flowers such as ginger root, peppermint, basil, or hibiscus flowers.

And adding artificial sweeteners to your booch will give it some sweetness, without adding any carbohydrates. The 3 artificial sweeteners I recommend are monk fruit, allulose, and erythritol.

Many people recommend using stevia, but there have been studies that found that stevia may negatively affect beneficial gut bacteria. And since these are the bacteria we’re trying to increase and replenish by drinking kombucha, it seems counterproductive to use a sweetener that may do the opposite.

4. Use a Hydrometer to Measure the Final Sugar of Your Kombucha

Once your keto kombucha is finished you’re probably going to want to know exactly how much sugar is in it so you can track it and make sure it won’t knock you out of ketosis.

You can actually use a tool called a hydrometer to measure the exact amount of sugar in your finished kombucha. It’s super simple to use and is almost essential for properly making keto kombucha.

I found a really affordable and high quality hydrometer kit that includes a hydrometer, test jar, protective case, cleaning brush, storage bag, cleaning bag, and instruction sheet. Plus it has free shipping! If you’d like to know the exact sugar content of your home brewed kombucha, you can find that kit on Amazon here.

5. Water Down the Final Kombucha

If you’ve done all of the above and after measuring the sugar level of your kombucha find that it’s too high for your liking, the last thing you can do to lower the sugar content of your kombucha is water it down before drinking it.

This will of course dilute the flavor, but it will be effective in lowering the amount of sugar per glass. You could also just choose to drink half a glass of undiluted kombucha if you’d prefer that.

The Ultimate Keto Kombucha Recipe (1 Gallon)



1 Gallon of Water 2 Tablespoons of Loose Leaf Black or Green Tea or 8 Tea Bags

1 Cup of Sugar 2 Cups of Starter Tea

SCOBY Flavoring of Choice

Step 1: Brew Sweet Tea

Bring a few cups of water to just under a boil. Then remove the water from the heat and mix in 3/4 cup of sugar. Next step 2 tablespoons of loose leaf tea or 8 tea bags for 30ish minutes.

Set aside the sweet tea to cool.

Grab 2 cup of starter tea from a previous kombucha brew. Starter tea is just unflavored kombucha from a previous brew that will help create an acidic environment in the tea early to prevent mold growth.

If you bought a SCOBY online it will come packaged in starter tea. If you've brewed before and didn't save any starter tea from a previous batch you can use a store bought bottle of unflavored kombucha or a splash of distilled white vinegar to give the brew its initial acidity.

If you’re making 1 gallon of keto kombucha, just use the instructions above.

If you want to make 2 gallons of keto kombucha, just multiply the amount of sugar, tea, and starter tea by two.

If you’re using an irregularly shaped container, or don’t want to brew your kombucha to the gallon, you can use the numbers below.

To make 1 cup of keto kombucha you need:

  • 0.0625 Cups of Sugar

  • 0.5 Tea Bags or 0.375 Teaspoons of Loose Leaf Tea

  • 0.125 Cups of Starter Tea

Just multiply these numbers by the # of cups of kombucha you want to make and you'll have the right amount of each ingredient.

Step 2: Add SCOBY and Starter Tea

Next we are going to add the sweet tea to our brewing vessel, and fill up whatever space remains with water. You can use cold water to help the tea cool down faster.

Once the sweet tea has cooled down to room temperature, add in the SCOBY and starter tea.

It’s important to wait until the sweet tea has cooled down to room temp to add the SCOBY because liquid that’s too hot or too cold can shock the bacteria culture.

Step 3: 1st Fermentation

After the sweet tea, SCOBY, starter tea, and water have all been combined in the brewing vessel, cover the top of the container with cloth or an old tea shirt and secure it with a rubber band. This will keep fruit flies and other bugs out.

Do not seal the jar with a lid or anything airtight, since we need oxygenated air to be able to flow in and out of the container to keep the SCOBY alive and functioning.

Normally we would wait 7-10 days for the SCOBY to ferment the sugar and nutrients in the tea into alcohol and healthy acids, but because we want as little sugar in the kombucha as possible it will probably be more like 16-20 days.

The time it takes to ferment will depend on the temperature of where you live and the activity level of your SCOBY, so to know when to stop fermentation just taste test the brew every day.

If you have a hydrometer you can use it in conjunction with the taste test to make sure that fermentation goes long enough to get the kombucha to a sugar content you’re happy with.

Step 4: 2nd Fermentation

We technically now have kombucha, but it’s not yet carbonated or flavored. To change that you’re going to first partially fill the brewing bottles with whatever no or low sugar flavoring you want.

You can also add any artificial sweeteners such as allulose, monk fruit, or erythritol to add sweetness without adding any carbohydrates.

Once the bottles have their flavoring in them, transfer the kombucha, probably via funnel, from the large container into all the bottles.

Also save 2 cups of it for starter tea for your next brew.

The bottles with kombucha and flavoring will now sit sealed at room temperature for 4-6 days. During this time you can make some more sweet tea and start a new brew of kombucha if you want. Then ideally, by the time you’re done drinking the brew you're making right now, the next batch will be just finishing.

Step 5: Refrigerate and Drink Up

The length of time 2nd fermentation takes will depend on the flavoring used and quality of your brewing bottles.

After the 4-6 days have passed, refrigerate the unopened bottles of flavored kombucha. The cold air in the refrigerator will slow down the fermentation process and calm the carbonation, decreasing the likelihood of an explosion when you open them.

After the bottles have been chilled, it's time to drink up!

If when you open the bottles there isn't enough carbonation, you can place them back at room temperature for a few days and they’ll resume the fermentation process and develop more carbonation.

At this point you can use the hydrometer again to check the final sugar level of your now finished kombucha. Hopefully it’s somewhere between 5-15g per 8 ounces and you can fit its sugar into your allotted carbohydrates.

If it has too much sugar for your liking, you can either dilute it with water or drink less of it when you drink it.

Final Thoughts

Congrats on making your own keto kombucha!

With practice and time, you should be able to figure out how to make your kombucha as low in sugar as possible, while still retaining the slightly sweet taste that makes it so delicious.

If you’d like to learn more about kombucha, how it can help a keto diet, and more home brewing tips, be sure to check out the rest of my website! Have a great day!

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