What Is Kombucha?

Kombucha is a lightly sparkling fermented tea made by combining sweetened tea with a SCOBY (Symbiotic Culture of Bacteria and Yeast). During fermentation, the beneficial microbes consume most of the sugar, producing organic acids, probiotics, and a refreshing tangy flavor.

For centuries, kombucha has been enjoyed around the world as a naturally fermented beverage that supports a healthy lifestyle.

Brewing kombucha at home is a wonderful way to create fresh, locally made wellness drinks throughout the year—especially during the darker winter months when nourishing daily habits become even more important.

Why Brew Your Own Kombucha?

Homemade kombucha offers several advantages:

• More affordable than buying bottled kombucha
• Customize sweetness and flavor
• Avoid unnecessary additives
• Reduce plastic waste
• Fun and rewarding fermentation project
• Naturally fizzy and refreshing

Many people also appreciate kombucha as part of a balanced diet because it contains:

• Organic acids
• Live cultures
• Tea polyphenols
• Antioxidants

While kombucha can be part of a healthy lifestyle, it’s not a miracle drink, and scientific evidence for specific health benefits is still evolving.

What You’ll Need

Ingredients

• 3 litres filtered water
• 6–8 black or green tea bags (or 15–20 g loose tea)
• 200–250 g organic sugar
• 250–500 ml plain, unflavoured kombucha (starter tea)
• 1 healthy SCOBY

Equipment

• Large glass jar (4-litre capacity)
• Clean cloth or paper towel
• Rubber band
• Wooden or silicone spoon
• Glass bottles with swing-top lids (for second fermentation)

Step 1: Brew the Tea

Bring the water to a boil.

Steep the tea for 10–15 minutes.

Remove the tea bags and stir in the sugar until completely dissolved.

Allow the tea to cool completely to room temperature.

Never add the SCOBY to hot tea—it can damage the beneficial microorganisms.

Step 2: Add the SCOBY

Pour the cooled sweet tea into your clean glass jar.

Add the starter kombucha.

Carefully place the SCOBY on top.

Cover the jar with a breathable cloth and secure it with a rubber band.

Step 3: Ferment

Store the jar:

• Out of direct sunlight
• At 20–26°C
• Undisturbed

Fermentation generally takes:

• 7–10 days for a sweeter kombucha
• 10–14 days for a more tart flavour

Taste every couple of days using a clean straw or spoon.

Step 4: Bottle

Remove the SCOBY and save:

• The SCOBY
• About 250–500 ml of kombucha

These become your starter for the next batch.

Pour the finished kombucha into bottles.

Leave about 2–3 cm of headspace.

Step 5: Add Natural Flavours (Optional)

This is where you can get creative.

Popular combinations include:

Berry & Mint

• Icelandic blueberries
• Mint leaves

Ginger Lemon

• Fresh ginger
• Lemon peel

Apple Cinnamon

• Apple slices
• Cinnamon stick

Rhubarb

Perfect during the Icelandic summer.

Sea Buckthorn

A vibrant Nordic favourite with bright citrus notes.

Step 6: Second Fermentation

Seal the bottles tightly.

Leave them at room temperature for:

2–4 days

This creates natural carbonation.

Afterward:

Refrigerate before opening.

Always open bottles carefully, as pressure can build up.

How to Care for Your SCOBY

Your SCOBY will grow a new layer with every batch.

To keep it healthy:

• Always use clean equipment.
• Wash your hands before handling it.
• Never use metal containers for long fermentation (stainless steel is generally fine for brief contact, but glass is preferred for fermenting).
• Keep enough starter tea for future batches.
• Store extra SCOBYs in a “SCOBY hotel” (a jar with finished kombucha).

Common Beginner Questions

My SCOBY sank. Is that okay?

Yes. A new SCOBY often forms on the surface while the old one settles.

Is mold normal?

No.

Mold appears fuzzy and may be green, black, blue, or white. If you see mold, discard the entire batch.

Healthy SCOBYs may develop brown yeast strands or darker patches, which are normal.

Why isn’t my kombucha fizzy?

Possible reasons include:

• Not enough second fermentation time
• Bottles not sealed tightly
• Too little fruit or sugar for carbonation
• Fermentation temperature too low

Can I reduce the sugar?

It’s best to follow a tested recipe. The sugar feeds the microbes during fermentation, and much of it is consumed before the kombucha is ready. Reducing it too much can interfere with the fermentation process.

Brewing Tips for Iceland

Because Iceland’s indoor temperatures can vary throughout the year:

• In winter, keep the jar somewhere consistently warm (around 20–24°C).
• Avoid placing it directly on cold windowsills.
• If your home is cool, fermentation may simply take a few extra days.

Using high-quality filtered water can also help produce a cleaner flavour, especially in areas with treated water.

Is Homemade Kombucha Safe?

When brewed using clean equipment and proper fermentation practices, kombucha is generally safe for most healthy adults.

However, some people should speak with a healthcare professional before drinking homemade kombucha, including those who are:

• Pregnant
• Immunocompromised
• Advised to avoid unpasteurised fermented foods

If anything smells putrid or you see mold, discard the batch.

Final Thoughts

Brewing kombucha is a simple, rewarding way to bring fermentation into your daily routine. With just tea, sugar, water, and a SCOBY, you can create a refreshing drink that’s uniquely your own.

Whether you enjoy it plain or infused with Icelandic berries, rhubarb, herbs, or other seasonal ingredients, homemade kombucha is a sustainable and satisfying addition to a wellness-focused lifestyle.

The first batch takes a little patience, but once you get started, you’ll have an ongoing supply of fresh kombucha and a SCOBY ready for future brews.

Ready to brew your first batch? You can purchase a healthy SCOBY and kombucha brewing supplies from Brew.is, an Icelandic homebrewing retailer. If you’re looking for more brewing guides and kombucha resources, You Brew Kombucha offers excellent tutorials for beginners.

• Iceland: Brew.is SCOBY
• International: You Brew Kombucha

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