Double Fermented Kombucha





Introduction: Double Fermented Kombucha

About: Deirdre hails from Upstate, NY, which is not New York City or Canada or really even "upstate". Deirdre is a struggling cosplayer and was shocked to find out that anime is not real and that she had ...

One time, while eating at a local health food store, the chef came over to me and began talked to me about fermented teas and drinks. Sounds gross, right? At first when I tasted the drink, it tasted and smelled like vinegar. But the more I drank, the more and more I began to really like the taste. This drink is called kombucha and is a fermented tea using a bacteria called a Scoby.

After spending way too much money on buying fancy kombucha teas at the store, I decided to make my own! It was a lot easier than I anticipated and with some patience you too can have your own fermented teas for significantly cheaper than any store! Change your flavors, multiply your batches, and enjoy!

Step 1: Materials

Tea (generally 4tbsp)
1- 1 1/2 cup Sugar
3tbsp Apple Cider Vinegar
3qts Water

Bottling Jars
Gallon Fermenting Jar
Cloth and rubberband

Step 2: Making the Tea

I am a tea addict, and maybe that's why I was drawn to kombucha. My tea collection is ranging on about 30 teas right now; I don't consider it a problem but more of a collection.

For your kombucha, boil 1 quart (4 cups) of water in your kettle. I like to measure it out before boiling and then add a little extra to boil off.

To pick your tea, you can use almost any tea you want! Bagged, loose, black, green, it's up to preference. One exception: make sure your tea is not "unsweetened" and make sure your tea is not herbal with pieces of fruit! I made a mistake in my first batch and used an herbal tea entirely from dried fruit. It didn't harm the Scoby but it has serious potential to weaken or kill your Scoby. The fruit has sugars that the Scoby is unable to process, and an unsweetened tea takes away natural sugars your Scoby needs to survive! You will flavor the kombucha later, so you just need a solid base tea for now.

Since I used a loose tea, I made my own tea bags by making little "dumplings" out of coffee filters. Some stores have disposable tea bags that are awesome if you don't want to go through the struggle of straining all your tea after it steeps.

Pour your water in and let the tea steep for at least 10 minutes. The longer you let it steep, the stronger the tea will be.

Add 2qts (8 cups) of cold water. Purified water is better than tap.

Step 3: Adding Sugar

While the mixture is still warm, add 1 - 1 1/2 cups sugar. This is your Scoby's food for the next 10 days. Too much sugar could overwhelm your Scoby, so don't go over 1 1/2 cups. I typically just use 1.

Mix the sugar in until completely dissolved. If you do this step while the tea is still very hot, make sure it doesn't caramelize at the bottom!

Let the mixture sit until room temperature is reached.

Step 4: Adding Vinegar and Scoby

I highly recommend buying a Scoby online instead of trying to grow one. Or, if you have a friend that brews, see if you can snag a baby Scoby off of them!

Your Scoby is an organism, and is susceptible to mold. To prevent mold, add 3 tablespoons of Apple Cider Vinegar to the mix. And here you wondered why it tasted like vinegar!

If you order a Scoby online, add the original kombucha the Scoby was packaged in. If you are making another batch from an already used Scoby, save some of your own kombucha and pour that into the new batch. This helps the process get started and gives the Scoby a familiar environment to thrive in.

Step 5: Cover and Wait

Your Scoby is now happily in your Kombucha and needs to some time to ferment. If your Scoby is not floating like mine is here, fear not! It will ferment just the same, each Scoby is different.

Cover with a cloth and seal with a rubber band. The cloth allows for some breathing in the bacteria culture to help the fermentation. If you do not have a cloth, a few coffee filters can be used.

Let the Scoby sit in an area of ~70F, not much colder. Colder temperatures will slow or halt the fermentation process. If you don't have the needed temperatures, above the fridge often gets warmer than other parts of the house. I keep my fermentation station in a cupboard above the fridge. DO NOT expose your Scoby to sun and just leave it on the counter!

Let it sit for 10-14 days.

Step 6: Remove and Check Your Cultures

In between this all, I started a second batch of a green tea kombucha; the more the merrier!

A few notes on the how your culture looks:

1. If you think it's mold, it's probably not. Mold has a very distinct look of a different, fuzzy, texture. Brown discoloration is completely normal and a pure white Scoby is also fine!

2. The tendrils are the yeast from fermentation. This is really good to see (shown in the second picture) and when you bottle, you will filter these bits out

3. You might notice a film later of a Scoby on top, but yours is still at the bottom. Congratulations, your Scoby had a baby! Save this for later for more brewing or give to a friend.

Step 7: Removing Your Scobys

Pour some of your tea into a large bowl and take your Scoby's out and place them in the bowl.

The Scoby needs to be in the kombucha liquid if not being used. I usually put them back in an unused fermentation jar or the large bowl and place them in the fridge till I use them again.

Placing them in the fridge puts them in a dormant state where they won't ferment. If you leave the Scoby out, you might need to check in on it once and awhile and give it more sugar to eat. Who knew a bacteria could be like a pet.

Step 8: Flavor Your Kombucha

For my black tea, I have decided to go with a fruit mash and for my green tea, ginger.

For flavoring kombucha you can also use a juice of your choice and use 1 part juice to 4 parts kombucha.

For the fruit:

If you have fresh fruit, that is obviously preferably to frozen fruit. Heat your fruit to release some of the juices and then mash the remaining berry mixture. Spoon the mixture into your bottles until it covers the bottom of the jar.

For the ginger:

Chop up your ginger and place a few chunks in each bottle.

The more of a flavor you add, the more the drink will pick up on it.

Step 9: Add the Tea

Using your funnel and strainer (you can get a combo funnel with a strainer that snaps right in, and that thing is a god send!), pour your tea into each bottle. Pour slowly to avoid overflow, and pour over the sink to avoid major spillage.

When full, seal up your bottles. If you have any left over that isn't enough for another bottle, give it to the Scoby in liquid that you set aside earlier!

Take your bottles and put them in the same spot your let your kombucha ferment. This will start the process of double fermentation. Now, the extra yeast left in the mixture will ferment whatever you added for flavoring, capturing the taste. Double fermentation is also a great way to create a carbonated kombucha.

Step 10: Strain the Tea and Enjoy!

After 3-5 days, you can stop the process of double fermentation. To do so, simply restrain your tea and pour it back into your bottle. I just put a colander over a bowl do do this process.

Watch out! Your kombucha may be very carbonated by this point and the pressure sealed bottles have a tendency to pop like a bottle of champagne. If it seems like you have less kombucha than you started, realize some tea may be lost in the process and the volume of your double fermentation items can be deceiving.

Put your tea in the fridge and enjoy! If you have any questions on the process, leave a comment below. Happy brewing!

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I thoroughly love kombucha! I am excited to see how to make it as I buy quite a bit. My favorite has chia seeds in it, which adds a whole other dimension.

The form of chlorine that can't be boiled or evaporated out is chloromine. It's a combination of chlorine and ammonia, and is often referred to as "chloromines" because multiple forms can be present.

You can check your local water jurisdiction whether they add it or not. It specifically wrecks havoc on bacteria and microorganisms and can only be removed effectively with reverse osmosis utilizing carbon filters or complete distillation. The most cost effective method of course is buying distilled water

Thanks for the Instructible!

If you want a cheap way to get a scoby, go to local health food store get a bottle and transfer into "white vinegar clean" quart jar with a cup of tea that had 4 tea spoons of sugar, make sure cooled. cover jar with cheesecloth and put into dark spot at proper temperature and a scoby will start to form, when you get one across the surface you are ready to make a half gallon batch. Starting this way kind of gave me a little satisfaction. TEMPERATURE is key to making faster and better batches. honestly only use white sugar, it works the best.... Ohh and I use Oolong and green tea mix mostly for mine.

2 replies

This is super cool- I heard making scobys was super hard, so thanks for sharing your method to make your own! I've definitely noted that temperature plays a huge factor in fermentation.

And I'll have to try oolong tea, that sounds good!

yes for sure temperature and also I think nice dark place.


So that's the white scum that floats at the top of my coffee pot after I leave the coffee in over the weekend! Maybe I should drink that too, I never thought it might be healthful!

1 reply

Oh, I wouldn't drink that! The scoby is a very carefully made culture full of healthy bacteria. I worry that what is in your coffee pot might not be such healthy mold. Even a scoby can get mold, and mold is still bad.

Kombucha must be a healthy and tasty drink because my sons drink it. I haven't tried drinking and making it yet maybe they will lead the way. Is it healthy?

3 replies

Kombucha is definitely an acquired taste but it is healthy! It looks scary when you put in all the sugar, but your culture eats all of that sugar during the fermentation. Kombucha aids in digestion and is high in probiotics (also good for digestion and detoxing your body). I've also heard of people developing less of a sweet tooth from drinking tons of it, but there's no real evidence on that. If you don't really like the taste, making your own is a good way to make it more tolerable or less vinegary to the taste buds.


What is "detox"? (I'm only aware of the "detox" that alcoholics go to in a usually unsuccessful attempt to stop drinking.)

In simple terms, a detox removes bad things from your body and ultimately it should make you feel better. In this case, the detox deals with what food and liquid you put into your body. Certain foods have things to "flush out" toxins from other foods in your body. Same concept as eating healthier, this can just be one helpful step to get your body feeling happier and healthier!

Yes, purified water is better than tap water, because tap water containing chlorine will kill scoby. All equipment that's been washed in chlorinated tap water, that will come into contact with the kombucha needs to be rinsed in filtered water or rain water first. Also do not use antibacterial soaps or detergents.
And only make kombucha in glass containers, not plastic or steel (although stainless steel can be used it will probably eventually rust because the culture is acidic. Plastic will leech).

5 replies

I use tap water, no problem. Boiling the water to make the tea gets rid of the chlorine.

Agreed: While it is true that chlorine is harmful to the scoby, air-drying your materials overnight will also make them safe, as this allows the chlorine to evaporate. I'm not sure if this is the case everywhere, but I have the good fortune of living somewhere it is! It's easy enough to grow your own scoby from a bottle of unfiltered kombucha you can buy at any health food store. So, it might be worth experimenting, if you live somewhere with reasonably good tap water.

Hello, "rosemaryknits":

Not necessarily so, since some municipalities use a form of chlorine that does *not* 'boil out'.
Can't remember the name, but it's *not* the same as regular chlorine, so it's much safer for the water dept. people.
Just not nearly as safe for you.

As chlorine is added to drinking water to kill bacteria, if water isn't boiled for at least 20min there is no guarantee of no chlorine (and even then not, if you haven't tested the chlorine level with test strips). The scoby you have might no longer have as full a complement of probiotic species of body-friendly yeast & bacteria that would otherwise been available had non-chlorinated water been used.
Leaving bucket of water in direct sunlight for a day will also get rid of chlorine, this is why swimming pools need to have chlorine added on regular basis.

These are really good and true points! I followed all these things while making but didn't mention them, thanks for adding this!!

I can't imagine this tasting good but if it has positive health effects I'll drink it...

Just WHAT therapeutic effects could be expected?

Is it an aphrodisiac.... NOVELDORK?

3 replies

The health effects aren't overwhelming unless you drink tons of it, just like anything else that's a "magic food". Don't rely on this drink as a sole source of positive health effects. If the taste is a concern, you can always sweeten with more fruit or ferment for less time

For therapeutic effects, it helps with detoxing your body and stabilizing your metabolism and usually when your body is in balance, it will help the mind as well.

I've never heard of it being an aphrodisiac but it seems like depending on what you second ferment with, it can be. You can use jasmine which would make it such.

Or how much you drink, perhaps...

Kombucha tastes (to me) like a cross between Liptonice soft drink (soda) but not that sweet, and apple cider but without that much alcohol. Its a probiotic of body-friendly yeasts and bacteria that help boost immune system (SCOBY = symbiotic colony of bacteria & yeasts). This means less colds and flu.