How to second-ferment kombucha for fizzy summer flavours

HOME MADE. MADE EASY. South African summer is here, and there's nothing better than a cold, fizzy glass of home-brewed kombucha on a hot afternoon. If your first brew tasted good but a little flat, the secret is the second fermentation: bottling your kombucha with fruit so it builds natural bubbles and big flavour. Here's how to do it, plus six easy flavour ideas using fruit you can find at any South African market this season.

First vs second fermentation: what's the difference?

The first fermentation happens in your big jar: sweet tea plus your SCOBY, covered with a breathable cloth, for about 7–14 days. This turns sweet tea into tangy kombucha.

The second fermentation happens in sealed bottles. You add a little fruit, juice or ginger, close the bottle, and leave it for 2–4 days. Because the bottle is sealed, the gas the yeast makes has nowhere to go, so it dissolves into the drink. That's your fizz.

What you'll need

• Finished kombucha from your first ferment (keep about a cup back, with your SCOBY, to start your next batch)
• Strong, pressure-rated swing-top (flip-top) bottles. Never use thin decorative glass for fizzy drinks
• Fresh or frozen fruit, fruit juice, fresh ginger or herbs
• A funnel and a strainer to keep bits out of your bottles
• A warm spot out of direct sunlight

How to second-ferment kombucha, step by step

1. Taste your first ferment. It should be pleasantly tangy with a little sweetness left. If it's still very sweet, give it another day or two.
2. Prep your flavour. Chop fruit small or purée it. As a rough guide, use about 2–4 tablespoons of chopped fruit or purée, or about 10–20% juice, per 500 ml bottle.
3. Fill the bottles. Add the fruit first, then use a funnel and strainer to pour in the kombucha. Leave 2–3 cm of space at the top.
4. Seal and wait. Close the bottles and leave them at room temperature for 2–4 days. In a hot Highveld or KZN summer, check after day 1 because things move fast in the heat.
5. Burp daily. Open each bottle carefully over the sink once a day to release built-up pressure, then reseal. This is the most important safety step.
6. Chill and enjoy. Once it's fizzy enough for you, move the bottles to the fridge. Cold slows fermentation right down and keeps the bubbles in. Strain out the fruit as you pour.

6 summer flavour ideas to try

• Mango and lime: ripe mango purée with a squeeze of lime. Tropical and very fizzy.
• Strawberry and mint: a few chopped strawberries and two or three fresh mint leaves.
• Pineapple and ginger: small pineapple chunks with a thumb of grated fresh ginger for a gentle bite. (Love pineapple? Try our Pineapple Tepache recipe too.)
• Granadilla: the pulp of one granadilla per bottle. Sharp, fragrant and very South African.
• Watermelon and basil: fresh watermelon juice with a torn basil leaf. Light and refreshing.
• Lemon and rooibos: a splash of cooled, strong rooibos with lemon zest and a teaspoon of honey.

Sugary fruits like mango, pineapple and grapes make the most fizz. Herbs and citrus zest add flavour but very little carbonation on their own, so pair them with a little fruit or juice.

Troubleshooting: flat, too fizzy, or too sour?

• Flat kombucha: Leave it a day or two longer, move it somewhere warmer, or add a bit more fruit or a pinch of sugar. Check your bottles seal tightly.
• Gushing when opened: It's over-carbonated. Chill bottles well before opening, burp more often, and shorten the second ferment in hot weather.
• Too sour: Your first ferment ran long. Bottle a little earlier next time, or add a splash of juice when serving.
• Little jelly blobs in the bottle: That's a baby SCOBY forming. It's harmless; just strain it out.

A stick-on temperature strip on your brewing jar makes it easy to see when summer heat is speeding things up. Around 22–28 °C is a comfortable range for kombucha.

Ready to brew your summer batch?

• New to kombucha? Start with our guide to brewing your first kombucha, then grab the Kombucha Elite Kit.
• Want the full setup? The Kombucha Elite Kit is our most complete kombucha kit.
• Keep it clean and bit-free with a stainless steel funnel with strainer.

Just starting out? Read our guide to brewing your first kombucha and The Ultimate Guide to Fermentation for Beginners. Happy brewing — enjoy the fizz!