Why isn't my kombucha carbonating?

Kombucha often remains flat when the bottles are too cold, not enough sugar was added for yeast to feed on during second fermentation, the bottles are not airtight, the SCOBY is weak, or the first fermentation was overly sour. Ensuring warmth, airtight bottles, and a sugar source usually solves the issue.

How do I get fizzy kombucha?

To get fizzy kombucha, fill bottles with finished kombucha, add a sugar source such as juice, fruit, or a small amount of sugar, seal the bottles tightly, and leave them at warm room temperature for 1–5 days. Burp daily to release excess pressure, then refrigerate to lock in carbonation.

What bottles are best for kombucha carbonation?

Swing-top glass bottles made for carbonation are the safest and most effective option. Thick glass beer bottles, champagne bottles, and Kombucha Kamp EZ Cap bottles also work well. Avoid mason jars, thin glass, and plastic containers for long-term use.

How much sugar do I need for carbonation?

A small amount of sugar is enough to create carbonation. Add 1–3 tablespoons of fruit juice or puree, a few pieces of fruit, or 1/4–1 teaspoon of cane sugar per bottle. The yeast consumes the sugar and produces carbon dioxide, which creates carbonation when trapped in the sealed bottle.

How long does second fermentation take?

Second fermentation usually takes 1–5 days depending on temperature, sugar levels, and yeast activity. Warmer temperatures encourage faster carbonation. Taste daily until you reach your preferred level of fizz, then refrigerate to slow fermentation.

How do I prevent kombucha bottles from exploding?

Use thick glass swing-top bottles, avoid excessive sugar, and burp bottles daily to release pressure. Refrigerate as soon as carbonation reaches your desired level. Keep bottles away from heat sources and do not overfill them.

Can I carbonate kombucha without adding sugar?

No. Yeast requires sugar to produce carbon dioxide. If no sugar source is added during second fermentation, the kombucha will remain flat. Even fruit-only flavorings must contain fermentable sugars to create fizz.

Why does my kombucha lose fizz once refrigerated?

Refrigeration slows fermentation and allows carbonation to stabilize, but if bottles are opened too soon or stored too long after reaching peak carbonation, some gas may escape. Using airtight bottles and chilling immediately after carbonation helps preserve fizz.

Kombucha Carbonation for Beginners (2025 Guide)

How to Get Fizzy, Bubbly, Effervescent Kombucha Every Single Time

Most people enjoy having at least some bubbles in their Kombucha. A fizzy glass of booch can be fun, adds to the flavor, and offers a “natural soda” type of experience, all of which have helped Kombucha become so popular. But it’s also true that Kombucha carbonation can be a tricky thing to master at first.

Utilizing these tips and tricks will help infuse your brew with more Kombucha carbonation than ever before. Just be careful not to overdo it! (Tips about that below too)

Once you have a routine, bottling a bubbly brew will be second nature!

However, if you landed on this page, chances are your Kombucha is either:

A) flatter than your enthusiasm,
B) exploding aggressively
C) wildly inconsistent — fizzy one week, bored the next.

Good news: Carbonation is a skill, not a mystery — and once you understand how it works, it becomes one of the most fun (and forgiving) parts of Kombucha brewing.

At Kombucha Kamp, we’ve helped countless brewers go from “Why is my Kombucha dead inside?” to “I just made natural soda that rivals the store stuff — come over and taste this RIGHT NOW.”

This guide will walk you through:

how carbonation actually works
how to choose the right bottles
how to flavor safely
how to avoid flat brews
how to avoid bottle bombs (important!)
and how to master the art of the perfect F2

Let’s get fizzy.

Why Kombucha Carbonates (The Quick, Friendly Science)

To get good carbonation, you don’t need to memorize chemistry — but a little understanding goes a long way.

Carbonation is created by happy yeast doing three things:

Eating sugar
Producing CO₂ (bubbles!)
Trapping that CO₂ inside a sealed bottle

That’s it. A three-step dance.

Yeast doesn’t care if the sugar comes from:

fruit puree
fruit juice
fresh fruit
honey (not during F1!)
cane sugar
sugar-rich herbs (ginger!)
syrups

If yeast has sugar, warmth, and an airtight bottle, it makes bubbles.

The rest is technique.

F1 vs F2: Understanding Where the Magic Happens

Before we talk bottles and flavors, we need to clear up the most common misconception:

F1 (First Fermentation)

The SCOBY lives here. It’s all about:

cultivating bacteria
balancing yeast
forming the new SCOBY layer
acidifying the brew for safety

There’s usually light natural fizz, but nothing dramatic.

The SCOBY does produce CO₂, but escapes through the cloth cover.

Let’s call this step “Creating the Base Brew”. This is liquid gold and serves as the canvas for all of your fizzy, flavorful creations.

F2 (Second Fermentation)

THIS is where carbonation is born.

This is your “bottle ferment.”

Here you:

bottle the Kombucha
flavor it
seal it
let carbonation build

If Kombucha were beer, F1 would be “brewing,” and F2 would be “conditioning in the bottle.”

All the magic happens here.

Tools You Need for Perfect Carbonation

(And a few to avoid so your bottles don’t turn into grenades.)

✔ BEST BOTTLES

Swing-top glass bottles (Grolsch-style)
Champagne bottles with crown caps

✔ GOOD (but less ideal)

Reused Kombucha bottles, only if:
- they’re thick
- the lids are in excellent shape
- the rubber seals are intact

✖ BAD or UNSAFE

Mason jars (not pressure-rated)
Thin recycled glass (won’t hold CO₂)
Plastic bottles over long-term (scratches harbor bacteria)
Cheap dollar-store bottles

If your bottles are flimsy?

Your fizz journey will resemble a crime scene. Seriously – this looks cool on social media, but having to clean fruit, fizz, and yeasty bits off of your ceilings, counters, carpets, and possibly pets… not fun. Trust me.

What Kombucha Needs to Carbonate (Non-Negotiables)

Think of carbonation as a recipe:

Sugar + Yeast + Warmth + Airtight Bottle = Bubbles

You must have:

✔ A healthy F1 (not overly acidic)

✔ Sugar added in F2 (even a little)

✔ Bottles sealed tightly

✔ Warm environment (75–85°F / 24–29°C)

✔ Time

You need none of the following:

✖ Fancy carbonation equipment

✖ Perfect SCOBYs

✖ Sterile conditions

✖ Expensive flavorings

You already have everything you need. Let’s move into flavors — because flavors = sugar = fizz.

Sugar Sources Ranked by Fizz Power

🥇 STRONG FIZZ

Fruit juices (grape juice, apple juice)
Fresh fruit puree
Ginger (a natural carbonation booster)
Cane sugar (¼–1 tsp per bottle)

🥈 MODERATE FIZZ

Fresh fruit pieces
Berries
Herbal syrups
Honey (for F2 only)

🥉 LIGHT FIZZ

Dried fruit
Vanilla
Herbs without sugar
Spices
Essential oils (never use these — they kill yeast)

🚫 NO FIZZ

Zero-sugar ingredients
Artificial sweeteners
Flavor extracts only (unless paired with sugar)

If fizz is the goal, always include something fermentable.

Step-by-Step: How to Carbonate Kombucha (The F2 Method)

This is the exact method we teach brewers worldwide:

Step 1 – Fill Bottles

Fill each bottle ¾ of the way with finished F1 Kombucha.

Step 2 – Add Your Sugar Source

Choose:

1–3 tbsp fruit puree
1–2 tbsp fruit juice
A few pieces of chopped fruit
¼–1 tsp cane sugar
1–2 tbsp ginger

Don’t overthink it — Kombucha is forgiving.

Step 3 – Leave Headspace

Leave 1–2 inches at the top.

Too much headspace = weak fizz

Too little = overfizz

Step 4 – Seal the Bottles

Airtight seal = carbonation guaranteed.

Step 5 – Store Somewhere Warm

Carbonation thrives around 75–85°F (24–29°C).

A cold F2 = flat Kombucha

A warm F2 = fizzy, happy Kombucha

Step 6 – Burp Bottles Daily

Especially for:

high-sugar flavors
warm homes
strong yeast activity

Burping = prevent explosions.

Step 7 – Refrigerate to Lock In Bubbles

Once it’s fizzy to your liking, refrigerate to slow fermentation.

Chill = fizz preservation

Warm = continued pressure

Step 8 – Enjoy!

Kombucha should hiss when opened — not scream.

Troubleshooting Flat Kombucha (Fix ANY Flat Brew)

If your Kombucha is flat, it’s for one of these reasons:

Reason #1: F2 was too cold

Cold = sleepy yeast

Solution:

Move bottles somewhere warm
Use a heat mat / brewers’ belt
Extend fermentation time

Reason #2: No sugar was added

Without sugar, yeast has no fuel.

Solution:

Add juice, puree, honey, or cane sugar

Reason #3: Weak bottles or bad seals

Store bottles don’t always seal tightly.

Solution:

Upgrade to swing-tops
Replace old rubber gaskets

Reason #4: F1 was too sour

Very acidic Kombucha = yeast slowdown.

Solution:

Shorten your first fermentation
Refresh with more sweet tea

Reason #5: Yeast levels too low

Over-strained Kombucha sometimes loses yeast.

Solution:

Stir or swirl your F1 gently before bottling
Use a more yeast-active batch
Add ginger (yeast booster!)

Reason #6: Kombucha was too cold when bottled

Refrigerated Kombucha = no fizz

Solution:

Always bottle room-temperature F1

Reason #7: Not enough time

Some batches fizz in 24 hours

Some take 3–7 days

Solution:

Be patient

Avoiding Bottle Bombs (Genuinely Important)

Exploding bottles are the #1 carbonation fear — and almost always preventable. We have a more comprehensive guide to avoiding this common pitfall HERE.