Summer Kombucha with Watermelon and Mint

Light, fresh and naturally sparkling: watermelon kombucha has everything a good summer drink needs. The combination of fruity watermelon, subtle acidity and fresh mint makes this kombucha the perfect refreshment for warm days.

Especially in summer, fruity second fermentations are particularly suitable for giving kombucha new flavors and more natural carbonation. Watermelon not only provides the typical summery taste but also natural sugar, which allows the living cultures to continue working during the second fermentation.

The result: a fermented summer drink with fine fizz, fresh fruitiness and a real summer drink vibe.

If you're new to the topic, you'll find everything about SCOBY, fermentation, and how to start making kombucha at home in our Kombucha Guide.

Kombucha naturally has a slightly sweet and sour note. Watermelon complements this taste perfectly because it is fresh, juicy, and pleasantly light.

Especially in second fermentation, the mild sweetness of watermelon harmonizes wonderfully with the fermented flavors of kombucha. At the same time, the fruit provides enough natural sugar for additional carbonation to form.

This creates summer drinks with living cultures that are light, fruity, and significantly more refreshing than classic soft drinks.

Second Fermentation

Prerequisite: finished Kombucha from first fermentation

Ingredients

• approx. 1.25–1.3 L finished kombucha (from first fermentation)
• 250 g watermelon, peeled
• 6 fresh mint leaves
• 1 tsp lemon juice
• 2 glass bottles
• Funnel

Preparation

1. Finely blend 250 g watermelon with 6–8 mint leaves.
2. Strain through a fine sieve. Yields approx. 150–180 ml juice.
3. Pour into each bottle:
   • 60–75 ml watermelon-mint juice
   • top up with approx. 625–640 ml kombucha
4. Seal bottles and ferment at room temperature for 1–3 days.
5. Carefully check pressure daily. Then chill.
6. Enjoy!

Important: Watermelon contains a lot of sugar and ferments quickly. Do not fill to the brim and do not leave unattended for too long.

Watermelon does not go directly into the first fermentation, but only into the so-called second fermentation afterwards.

As soon as your kombucha tastes slightly sweet and sour, it is bottled together with watermelon and herbs. In the sealed bottle, the cultures continue to work and develop natural carbonation and more intense fruit aromas.

Watermelon ferments relatively quickly. Therefore, it is important not to fill the bottles to the brim and to carefully check the pressure daily.

For extra fizz, the following help:

• pressure-resistant bottles
• sufficiently active cultures
• some room temperature
• daily venting

The longer the second fermentation lasts, the fizzier and less sweet the drink becomes. Usually, 1–3 days are completely sufficient.

Watermelon kombucha can be wonderfully combined with fresh herbs.

Particularly popular are:

• Mint
• Basil
• Lime

Mint provides extra freshness and an almost spa-like summer drink character. Basil brings a slightly tart, aromatic note, while lime further enhances the fruity acidity of the kombucha.

This creates creative summer drinks that are perfect for warm days or conscious daily rituals.

Fermented through the summer

Watermelon kombucha shows how versatile kombucha second fermentations can be: fruity, light, and full of natural carbonation.

Functional drinks — homemade. For vibrant cultures, conscious routines, and summer drinks that do good.

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