Green Tea Watermelon Kombucha Recipe + Kombucha FAQ!

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So you’ve gotten your kombucha starter kit, you’ve brewed some batches, and maybe you’ve made some fun flavors already. Ginger kombucha, anyone? The health benefits of this funky fermented tea are desirable. But as warmer temperatures start approaching, and stands of ripe watermelon start dotting the country roads, are you dreaming of a new, sweet kombucha to pour over ice on those hot summer days?

If so, you’re in luck! You already know making your own kombucha is fun and rewarding, and you’ve probably already reaped some of the digestive benefits of the tasty probiotic drink. It’s so easy to experiment with flavors in your second fermentation, and when you do it using fresh fruit, or even just watermelon juice, you won’t have to use any added sugar to get that bubbly kombucha you’re after!

Really, it’s so simple you barely need a recipe. There are only a couple of considerations. Are you using narrow mouth, swing-top bottles? If so, you might want to throw all your watermelon into your blender container and blend it into a juicy pulp before adding it, to make it easier to clean your bottles. If you’re reusing old kombucha bottles or bottling into mason jars, you can just roughly chop your watermelon into chunks and toss it all together!

After your next batch is brewed, just use this simple ratio of fruit to kombucha: 1:4. So for every one cup of kombucha, you would add 1/4 cup watermelon juice (or about 1/2 cup fresh chopped watermelon chunks.) Combine at that ratio and store at room temperature for 2-4 days, then transfer to the refrigerator for another day or two, then enjoy!

Some fun ideas to enjoy it:

Serve over ice, garnished with fresh mint leaves for watermelon mojito kombucha mocktails.

Blend with tequila, lime juice, and ice (or frozen watermelon) and serve in a salt-rimmed glass for gut healthy margaritas. (Skip out on the tequila for a cocktail version!)

Serve either drink in hollowed-out personal size watermelons for extra cute points!

Wait, what?

If you’re just getting started with homemade kombucha tea, here’s a really simple explanation and a recipe for how we make ours.

What is Kombucha?

Most simply, kombucha is a sweet tea that has gone through a fermentation process. The kombucha SCOBY (symbiotic culture of bacteria) is a type of good bacteria that grows when fed, very much in the way a sourdough starter does. Throughout the brewing process, the SCOBY feeds off the nutrients from the leaves and sugar in the sweetened tea, and after a number of days, transforms your tea base into a delicious drink!

So… is it alcoholic? Vinegar?

Well, yes, actually. It’s sort of…both. In the fermentation process, yeasts in the SCOBY convert sugars into alcohol and then the bacteria convert that alcohol to vinegar. The alcohol content is completely minimal, usually less than one percent. So don’t worry if you’re the designated driver; the acetic acid and amino acids present in the final brew have more in common with apple cider vinegar than beer!

Why should I drink it?

Many people claim to enjoy the health benefits of kombucha, ranging from things like improved gut health, a better immune system, less anxiety, and general improved overall health. You can read more about these benefits HERE. Other people enjoy kombucha as an alternative to sugar-heavy soft drinks or alcohol-laden cocktails.

How do I get started?

The easiest way is to get a ‘start’ of an active culture, either from a friend who is already brewing kombucha or by purchasing a kombucha kit. You can grow your own SCOBY from cultures in bottled, store-bought raw kombucha, but it takes a little longer and can be harder to find. Many kombuchas sold in stores have gone through some kind of pasteurization process and are no longer truly raw. However you get your starter, it should come with a section of layered, mushroom-like SCOBY and several ounces of starter liquid.

What type of tea do you use?

Kombucha can be made with black tea, green tea, white tea, or oolong tea. These are all leaves of the camellia Sinensis plant and give you the cleanest flavor and best impact. Avoid herbal teas or ones flavored with oils, such as earl grey. If possible, use organic tea to avoid pesticide contamination. You can use loose leaf tea or tea bags.

I have a starter, now what?

First, find a clean gallon jar, a finely woven cotton tea towel, and a rubber band that fits the top of your jar. We use a 1 and 1/2 gallon drink dispenser with a spigot. This makes it much easier to transfer to bottles after it’s brewed. It’s not essential, but if you want to stick with your brewing, it definitely will make your life easier! Once you’ve chosen your vessel and ‘lid,’ it’s time to make your tea!

Gather up your simple ingredients: tea, sugar, and water. Use a kettle to heat some water.

In a glass or plastic measuring cup, use about 2 cups of hot water to brew your tea. Add sugar to the hot tea and stir to dissolve, again, using a wood or plastic spoon.

Avoid using metals when dealing with your kombucha.

Transfer tea to your gallon jar and add 13 cups of cold or room temperature water. Make sure it’s not too hot or too cold.

Finally, add your new SCOBY and the starter tea it came in. It should have some small clumps of yeasty bits, don’t be alarmed, and don’t strain them out. If you have to touch the SCOBY, only do so with very clean hands.

Give it a gentle stir, cover the top of the jar with the cotton towel and use your rubber band to secure it. Set the jar in a fairly dark place, or at least out of direct sunlight, but avoid areas with cooler temperatures.

Kombucha prefers to live somewhere where the ambient temperature is between 68 and 78. Once you’ve found its happy place, celebrate! Your first fermentation is underway!

After about a week, your SCOBY will probably be growing a new layer. It will be a thin, jelly-like skin, usually floating on the top of the tea’s surface. At this point, you can taste it! Scoop out a spoonful, pour out a splash, or dip a straw in to taste a sip. It should be a nice balance of sweet and sour. If it’s still fairly sweet, continue brewing and check on the flavor daily. There’s really no right or wrong here, just use your own taste preference. You might feel lost in the beginning, but as you get a few batches under your belt, you’ll learn what you like your finished kombucha to taste like. At this point, you can bottle it up, refrigerate until cold, and enjoy, or, use fruit or juice to start secondary fermentation.

Second Fermentation and your next batch of Kombucha

You can use the watermelon recipe from above, or play with other flavors. Ginger and lemon are very popular, and strawberry is one of my favorites! You can use whole or chopped fresh fruit, dried fruit, or fruit juices. Stick to the 1:4 ratio for most everything, except lemon and ginger. Since they are such strong flavors, I would reduce them by half. This second fermentation and the addition of more natural sugars is what will make your kombucha a yummy, fizzy drink!

Add fruit or juice to your bottle first, then top off with kombucha. If you’re using a container with a spigot to brew, this process is super simple. If not, grab an assistant to help with narrow bottles, holding funnels, and pouring from a big jar. It may be easier to simply use clean hands to remove the SCOBY to a clean plate while you process the batch. Set aside about 8 ounces of liquid from this batch to add to your next brew.

Leave about 1 inch of space at the top of your bottles, seal securely, and store at room temperature for 2-4 more days to allow for more fermentation. If you’re concerned about glass bottles exploding from the pressure, simply ‘burp’ your bottles each day by cracking them open. This releases any buildup of pressure. After a few days, transfer to the refrigerator and store until you drink them!

Now, simply repeat the steps from your initial batch to set up your next one. Brew tea, sweeten, add cool water to equalize the temperature. Transfer to your brewing vessel and add your SCOBY and starter tea. Cover, let ferment, and keep repeating!

More FAQ

Does kombucha go bad? How do I store kombucha? How long will my homemade kombucha last?

Technically, a true live raw kombucha could last forever. However, because of the SCOBY culture it contains, it is a living organism and it will continue fermenting all its life. This won’t really make it ‘bad,’ but it can affect the taste and cause it to become too sour and bitter to be enjoyable to drink. The best way to keep this fermented drink enjoyable for a long time is by storing it at a cold temperature in the refrigerator after your second fermentation is complete.

Kept in the fridge, unopened bottles of homemade healthy kombucha can last 1-3 months in a sealed bottle. If they have been through a second fermentation with fresh, frozen, or dried fruit, be aware of obvious signs of spoilage, such as visible mold growth. If that happens, the entire bottle should be discarded.

Now, if we’re talking store-bought kombucha, things can differ a little bit. While any kombucha from the grocery stores will have a printed expiration date, they may not all require the same storage treatments. Some brands make shelf-stable kombucha that can be stored in the pantry instead of requiring refrigeration. Just read the bottle to determine what you should do. As a rule of thumb, however, unopened store-bought bottles of most kombucha brands can last in the fridge for up to 8 months. However, it should be consumed within 7 days of opening.

Some older bottles of kombucha may have yeast sediment at the bottom of the bottle or a baby SCOBY-like skin floating on the top. These are both harmless and can be strained out before you drink it.

How do I know if my SCOBY has gone bad?

For the most part, with proper handling and care, your SCOBY should stay healthy for years! They may change in color slightly, or develop some dry or brown spots. The good news is though, generally, the low ph levels inhibit the growth of anything icky. In extreme cases, something may go wrong, and it may grow mold. This is an obvious sign of spoilage and it should all be discarded. This has never happened to us in the 5 years we’ve been brewing ours, but just in case it ever does, it’s a good idea to keep a small ‘backup’ SCOBY and starter alive in a separate vessel.

What if my kombucha brewed too long?

It’s ok! Life happens. Sometimes, we don’t have time to process a new batch in time. Sometimes, the warm temperature in your house can make a batch brew faster than you expected. Don’t panic! You just made a batch of kombucha vinegar. You can use it as a vinegar substitute in recipes, salad dressings, or even for cleaning. I used my last over-brewed batch to clean my kitchen drain. Or ask around and see if you know anyone who loves the extra tart taste. A lot of people do! Absolute worst-case scenario, you can just dump it out. It feels painfully wasteful, I know, but it happens. Thankfully, it won’t kill your SCOBY or hurt your next batch. Just move on to the next one!