What Is Kombucha? A Beginner's Guide to Fermented Tea

Kombucha is a naturally fermented tea made from tea, sugar and a SCOBY. But what actually happens during fermentation, why does kombucha taste tangy and fizzy, and what makes traditionally brewed kombucha different?

If you've noticed kombucha appearing in cafés, farmers' markets and fridges across the UK, you may be wondering what exactly it is.

Kombucha is a fermented tea drink with a distinctive balance of gentle acidity, natural fizz and complex flavour. It has been made for generations using a simple process: tea is sweetened, combined with a SCOBY and left to ferment over time.

At Vesna, we believe good kombucha shouldn't be rushed. Our small-batch kombucha is brewed in glass and given time to develop its flavour naturally, creating a drink that feels as much like a ritual as it does a refreshment.

So, let's start at the beginning.

What is kombucha?

Kombucha is a fermented tea drink traditionally made from brewed tea, sugar, water and a SCOBY.

The word SCOBY stands for Symbiotic Culture of Bacteria and Yeast. It is the living culture responsible for transforming sweetened tea during fermentation.

During this process, naturally occurring yeasts and bacteria interact with the sweetened tea. Over time, the flavour changes from sweet tea into something more complex, lightly tart and aromatic.

The result is kombucha: a refreshing fermented drink with a characteristic tang and, depending on how it is brewed and bottled, a natural sparkle.

While kombucha is now widely enjoyed as an alternative to soft drinks and alcoholic drinks, its origins are much older than today's wellness movement.

How is kombucha made?

At its simplest, kombucha requires only a few key ingredients:

• Tea
• Water
• Sugar
• A SCOBY
• Time

The process begins by brewing tea. Traditionally, black or green tea is used because the tea provides the nutrients needed during fermentation.

Sugar is then added to the brewed tea. This isn't simply there to make kombucha taste sweet. During fermentation, the microorganisms in the culture use the available sugars as part of their activity.

The sweetened tea is then combined with the SCOBY and left to ferment.

And this is where the transformation happens.

1. Brewing the tea

The process begins with carefully brewed tea.

At Vesna, we use tea as the foundation of our kombucha before adding carefully selected botanical ingredients to create each flavour.

2. Adding the SCOBY

The SCOBY is introduced to the sweetened tea.

This culture contains a community of yeasts and bacteria that work together throughout fermentation.

3. Fermentation begins

Over time, the culture transforms the sweetened tea.

The flavour becomes less sweet and increasingly complex, with acidity developing alongside aromatic and fermented notes.

This is why kombucha can taste very different from ordinary iced tea.

4. Flavour development

Once the base kombucha has developed, ingredients can be introduced to create different flavour profiles.

At Vesna, we work with ingredients such as hibiscus, rose, elderflower, chamomile, holy basil, cucumber, lemon balm, ginger and lemon.

The result is a range of kombuchas designed around flavour first — from floral and delicate to bright, citrusy and warming.

5. Bottling and natural carbonation

Kombucha can develop natural carbonation during bottling and a second stage of fermentation.

This creates the gentle fizz that makes kombucha so refreshing.

It also means that every bottle can have its own character. You may notice a little sediment, variation in flavour or a particularly lively bottle — all natural characteristics of a minimally processed fermented drink.

How long does kombucha take to ferment?

One of the biggest differences between traditionally brewed kombucha and faster commercial processes is time.

Kombucha fermentation can take several days or longer depending on the recipe, temperature, culture and desired flavour.

At Vesna, we allow our kombucha to develop over approximately 21 days.

Why?

Because fermentation isn't something we want to rush.

As the kombucha ferments, its flavour evolves. Sweetness, acidity, tea character and botanical flavours gradually come together.

Our philosophy is simple:

Your kombucha shouldn't be ready in 48 hours just because it can be.

We believe giving fermentation time creates a deeper, more interesting drinking experience.

What does kombucha taste like?

If you've never tried kombucha before, the flavour can be difficult to compare to anything else.

Kombucha is generally:

• Lightly tart
• Refreshing
• Aromatic
• Gently sparkling
• Less sweet than traditional soft drinks
• Complex rather than one-dimensional

The exact flavour depends on the tea, fermentation process and additional ingredients.

For example, ginger and lemon kombucha can be bright, fresh and citrusy, while hibiscus, rose and elderflower kombucha can have a more floral and delicate character.

This variety is one of the things that makes kombucha interesting.

It's not simply one flavour of drink — fermentation creates a foundation that can be paired with an almost endless range of botanical ingredients.

Is kombucha alcoholic?

Because kombucha is fermented, it can contain small amounts of naturally occurring alcohol produced during fermentation.

The amount can vary depending on the brewing and fermentation process, storage conditions and other factors.

This is one reason kombucha shouldn't automatically be thought of as identical to a conventional soft drink.

At Vesna, we also love kombucha as part of a more mindful drinking ritual — whether you're replacing an alcoholic drink, looking for something interesting to serve at dinner, or simply want a sophisticated drink to enjoy from a beautiful glass.

What is a SCOBY?

SCOBY stands for Symbiotic Culture of Bacteria and Yeast.

It is the living culture used to ferment sweetened tea.

If you've ever seen a kombucha SCOBY, you may have noticed that it looks quite unusual — often like a pale, rubbery disc floating on the surface of the tea.

Don't worry. That's exactly what it's supposed to look like.

The SCOBY is an essential part of traditional kombucha fermentation. It creates the environment in which the yeasts and bacteria can interact with the sweetened tea and transform it over time.

For anyone interested in fermentation, the SCOBY is also a fascinating reminder that some of the most interesting food processes happen through living cultures rather than industrial shortcuts.

What is the difference between raw and pasteurised kombucha?

You'll often see the words raw, unpasteurised or pasteurised when shopping for kombucha.

Pasteurisation uses heat to reduce or eliminate microorganisms in a food or drink.

An unpasteurised kombucha has not undergone this heat treatment after fermentation.

At Vesna, our kombucha is raw and unpasteurised, which means we keep the drink as close as possible to its fermented form.

Because kombucha is a living fermented product, it should be treated differently from a conventional shelf-stable soft drink. Our bottles are kept chilled, and we recommend following the storage instructions on the bottle.

Is kombucha a healthy drink?

Kombucha is often associated with wellness, but it's important to look beyond the health claims you see online.

Kombucha is first and foremost a fermented tea drink.

Its nutritional and microbiological characteristics can vary significantly depending on the tea, ingredients, fermentation process and production method. Claims that kombucha can "detox" the body, cure illnesses or provide specific medical benefits aren't something we rely on at Vesna.

Instead, we focus on what we can control:

quality ingredients, careful fermentation, thoughtful flavour and a slower approach to making kombucha.

For us, wellness isn't about making exaggerated promises.

It's about creating small everyday rituals that feel good.

How should you drink kombucha?

There is no complicated ritual required.

Kombucha is delicious straight from the bottle, but you can also pour it into a wine glass or tumbler over ice and add a slice of lemon, fresh herbs or seasonal fruit.

Try serving it:

With lunch
A refreshing alternative to a sugary soft drink.

Before dinner
A bright, sparkling drink to start the evening.

At a dinner party
Serve kombucha in beautiful glasses alongside food.

As an alcohol-free ritual
Pour it slowly into a favourite glass and make the occasion feel special.

After a walk or at the end of the day
Sometimes the simplest ritual is the best one.

At Vesna, this idea of ritual is at the heart of what we do.

Kombucha doesn't need to be complicated to feel special.

Why we take our time with kombucha

There are faster ways to make kombucha.

That's not the way we choose to do it.

Vesna was inspired by the kombucha the founder grew up with in Ukraine — homemade, shared and made with patience rather than mass-produced.

Today, we continue that spirit in small batches in the UK.

Our kombucha is glass brewed, unpasteurised and given approximately 21 days to ferment.

We use carefully selected teas and botanical ingredients, with no artificial flavours or colours.

Because we believe fermentation is something worth respecting.

Good things take time.

Ready to discover kombucha?

If you're new to kombucha, start with the flavour that sounds most like you.

Glow — hibiscus, rose & elderflower
Floral, elegant and beautifully refreshing.

Calm — chamomile, holy basil & cucumber
Soft, botanical and sophisticated.

Clarity — green tea & lemon balm
Fresh, clean and herbaceous.

Energy — ginger & lemon
Bright, zesty and warming.

Explore the Vesna collection and discover small-batch kombucha brewed slowly, naturally and with care.

SHOP VESNA KOMBUCHA