Healthy Scoby or Moldy Scoby: How Do I Know? (FAQ) (2024)

When you start fermenting kombucha, it is normal to wonder if your kombucha scoby is healthy. Everything seems so strange!

You might be asking yourself:

“Is my kombucha scoby mouldy?”

“How does a healthy kombucha scoby looks like?”

“Are these black filaments mould?”

Don’t worry: 99% of the time, the kombucha scoby is perfectly healthy. It can appear in all sorts of shapes and forms. Indeed, a scoby is quite funky!

This article will help you identify what’s going on in your jar, so you know if your scoby (and your kombucha!) is doing well.

To find the answer to your question, click directly on the topic that interests you:

  • Is My Kombucha Scoby Is Still Alive?
  • My Kombucha Scoby Is Sinking
  • White Layer on Top of My Kombucha
  • Brown Stuff in My Kombucha
  • New Scoby Forming in My Bottle
  • Is the Colour of My Scoby Normal?
  • My Kombucha Is Not Fizzy
  • My Kombucha Is Too Acid
  • Can Kombucha Be Dangerous?
  • How Do I Know If My Scoby Is Dead?
  • Why Did My Scoby Die?
  • Is My Kombucha Scoby Mouldy Or Rotten?
  • Maggots in My Kombucha

Identifying a Healthy Kombucha Scoby

Let’s face it – a kombucha scoby is a strange thing for the inexperienced! Indeed, this cellulose film created by symbiotic colonies of bacteria and yeast has a rather astonishing appearance.

It can take all sorts of shapes, colours, and behaviours. Fortunately, they are normal most of the time. You have to learn to appreciate your scoby, no matter how unique they may be!

This section gives you an overview of normal and healthy kombucha scobies, which is the case 99% of the time.

How Do I Know If My Kombucha Scoby Is Still Alive?

To find out if your kombucha scoby is doing well, just test it!

Make a normal kombucha recipe by adding the scoby to some sweet tea. Wait a week and observe.

Signs that everything is fine:

  • A new scoby is forming on the surface/the scoby is getting bigger
  • Your sweet tea has become tangy
  • Small bubbles are forming

It is normal (especially at the beginning) for only one of these signs to appear.

The most important is that the tea becomes less sweet and more acidic.

Why is My Kombucha Scoby Sinking?

No worries, it’s normal! Young kombucha mothers tend to sink to the bottom of the jar.

You don’t have to do anything. A new film will gradually form on the surface.

Healthy Scoby or Moldy Scoby: How Do I Know? (FAQ) (1)

For more information, read Why is my kombucha scoby sinking?

What Is the White Layer on Top of My Kombucha?

The white layer is a new scoby that has formed on the surface of your kombucha. Its appearance is often smooth.

The kombucha scoby covers the entire surface of the sweet tea to help protect it from external contaminants. Do not touch it!

It is perfectly normal; it will gradually thicken, and you can use it for your next kombucha recipe.

What Is the Brown Stuff in My Kombucha?

The small brown or black stringy clumps are colonies of yeast and tea residue. They are completely normal and safe!

Healthy Scoby or Moldy Scoby: How Do I Know? (FAQ) (2)

These colonies often form long filaments that hang under the kombucha scoby.

Yeast can also merge with the existing layer, or even form in bottles after bottling. You can choose to remove them, or not.

A New Scoby Is Forming in My Bottle! Is This Normal?

Yes, even in the bottle, the microorganisms in kombucha are still at work.

Healthy Scoby or Moldy Scoby: How Do I Know? (FAQ) (3)

The little scobies created in the bottles often merge with yeast colonies, resulting in small gelatinous layers or brown filaments, and sometimes both.

When this happens, it just means that your kombucha scoby is healthy and strong!

You can choose whether or not to filter your kombucha before you drink it. The layer is entirely edible and full of life.

Is the Colour of My Kombucha Scoby Normal?

The colour of the kombucha scoby is not important.

In practical terms, a kombucha scoby is like a sponge. The tea used will change the colour of the scoby: black tea will give a darker scoby, while green tea will give a lighter scoby.

There can also be different colours, tints, or parts within the same scoby. Once again, this is all perfectly normal.

Healthy Scoby or Moldy Scoby: How Do I Know? (FAQ) (4)

Growing scoby: the different colours are due to the different thicknesses of the kombucha scoby.

My Kombucha Is Not Fizzy. Is My Scoby Dead?

No! Bubbles are not an indicator of your kombucha’s health. Several factors influence the amount of sparkling:

  • The bottles used
  • The ingredients
  • The scoby’s age
  • The temperature

And much more! To learn more about this, read How to Make Fizzy Kombucha.

What to Do If My Kombucha Is Too Acid?

You have left your kombucha to ferment too long, and it has become too acidic for your taste? Know that it is still safe to consume and full of good microorganisms.

You can dilute a kombucha that is too acidic with sweet tea or with a younger and therefore sweeter kombucha.

You can also let it turn into kombucha vinegar by fermenting it longer or use this kombucha as a starter culture for your next recipe.

Reduce the fermentation time of your kombucha next time!

Can Kombucha Be Dangerous to Health?

There is no danger in consuming kombucha because its acidity protects it from contamination.

Read: Are there any dangers to homemade kombucha?

If, however, fermentation has gone wrong and mould has formed or contamination has occurred, then yes, there may be a health risk (as with any food, for that matter). Read on to find out more.

Identifying Sick or Dead Kombucha Scoby

It is extremely rare for kombucha scobies to get sick, or even die. This section will help you identify these rare occurrences.

How Do I Know If My Kombucha Scoby Is Dead?

The only way to know if your kombucha scoby is dead is to test it in a new kombucha batch and wait a few weeks.

If your sweet tea has not become acidic after 15 days, then you can definitely conclude that your kombucha scoby has died.

Why Did My Kombucha Scoby Die?

Several situations can lead to the death of a kombucha scoby:

An Exhausted Scoby

A scoby can usually survive without being fed or oxygenated for:

  • 6 months in the fridge
  • 3 weeks at room temperature

Beyond this time, a scoby left in a closed jar or not fed with new sweet tea will eventually exhaust itself. It will lose its ability to produce kombucha. To learn more, read How to Store A Kombucha Scoby.

When in doubt, you can make a small amount of kombucha to test your scoby’s vitality.

A Tea That Is Too Hot

Bacteria and yeast do not survive at too high temperatures.

If the tea is too hot for you to dip your finger in, then it is too hot for the kombucha scoby!

If the kombucha scoby was added to tea that was too hot, it’s probably what killed it. Ouch! In that case, you’ll have to start again with a new scoby.

Is My Kombucha Scoby Mouldy, Or Rotten?

In rare cases, mould can grow on your kombucha scoby.

Mould is fairly easy to recognize because it:

  • Is always on the surface
  • Is white, blue, or greenish
  • Has a hairy or dusty appearance

Remember, mould is easy to identify and looks like what you would find on food forgotten at the bottom of the fridge.

Healthy Scoby or Moldy Scoby: How Do I Know? (FAQ) (5)

What if There Are Maggots in My Kombucha?

If your kombucha scoby has been contaminated by fruit flies, you should dispose of it.

Fruit flies, or drosophila, are the #1 enemy of the kombucha fermenter. They are attracted by the smell of kombucha and will do anything to lay their eggs in it. If you find maggots in your kombucha, throw it all out!

To avoid this unfortunate situation, use a tightly woven cotton cloth to cover the jar. Cheesecloth and muslin have too large a mesh and fruit flies can get through them.

Get Started!

  • Read How to Make Kombucha
  • Try our Kombucha Recipes
  • Discover “The big book of kombucha”
  • Buy a Kombucha Brewing Kit
  • See our “Making Kombucha” Online Course
Healthy Scoby or Moldy Scoby: How Do I Know? (FAQ) (2024)

FAQs

Healthy Scoby or Moldy Scoby: How Do I Know? (FAQ)? ›

A SCOBY can have streaks of brown or black on it – this is just leftover remnants of tea from the last brew. You can tell if a SCOBY is moldy by the presence of mold. And mold does NOT look like leftover tea bits. A moldy SCOBY has white or gray fuzzy growths on it.

What should a healthy SCOBY look like? ›

Normally a SCOBY will be somewhere between a tan brown and a creamy white colour. The surface may be smooth, uneven, have holes or even bubbles – these are all pretty standard variations.

How do I know if my SCOBY is moldy? ›

Mold can be white, green, black, blue, red...if you're seeing interesting bright colors, that's a bad sign. SCOBYs are usually white/cream to brown in color, but fuzzy, snowy white is bad, especially if it's a layer on top of your brew vessel.

When should you throw out a SCOBY? ›

You will only need to replace your SCOBY if it has developed mold or if it is continuously struggling to ferment. Often with struggling SCOBYs, things can be done to help bring balance to your culture depending on the situation, and you won't need to start over completely.

How do you tell the difference between a healthy SCOBY and a bad SCOBY? ›

A healthy SCOBY is always white or light tan, or some shade in between. A darker brown SCOBY might just mean that the SCOBY is older, and probably won't work to brew kombucha. A SCOBY can have streaks of brown or black on it – this is just leftover remnants of tea from the last brew.

How do I know if my homemade kombucha is safe? ›

Maintain pH level of 4.2 or lower. If the pH level goes above 4.2 during fermentation, too much acetic acid may be produced, which can put the brakes on bacteria growth. A product with too much acid can lead to adverse health effects. Use pH strips to verify pH levels in your homemade kombucha.

Can you get sick from a bad SCOBY? ›

As a result, the SCOBY can produce harmful bacteria and aspergillus (a toxin-producing fungus), which can cause illness.

How do you remove mold from a SCOBY? ›

But if you do experience mold, it will develop on the top of your brew, where it's exposed to oxygen. If you do experience mold, you MUST DISCARD EVERYTHING and start with a new SCOBY and starter liquid from your SCOBY HOTEL, or purchase a new SCOBY from us!

How do I know when my SCOBY is done? ›

When the scoby is about 1/4-inch thick, it's ready to be used to make kombucha tea — depending on the temperature and conditions in your kitchen, this might take anywhere from 1 to 4 weeks.

Is my SCOBY dead if it doesn t float? ›

In time, a new SCOBY will start slowly forming on the surface and thicken over time. So rest assured, a sinking SCOBY is nothing to worry about! Now that we've debunked the SCOBY position myth, you can celebrate knowing your batch is healthy!

Should SCOBY sink or float? ›

When you first put your SCOBY into your sweet tea in the brewing vessel, it might sink. Or it might float. Both are OK. Oftentimes, it'll end up making it's way to the top of the brewing vessel in the next few days, where it'll conjoin with the new SCOBY that's forming.

What is the lifespan of a SCOBY? ›

The scoby will then go dormant and can be kept for up to 6 months. However, we've already seen scobys that had been forgotten for over a year in a corner of the fridge come back to life without any problem.

What does a rotten SCOBY look like? ›

DEVELOPING BABY SCOBYS

A moldy or dead scoby is quite distinctive, and there is no mistaking it when you see it. The mold will be white or colorful, fuzzy and dry. It can appear as spots on the scoby, or cover the scoby altogether. A dead scoby will be black.

What does an old SCOBY look like? ›

The mother scoby is VERY dark brown, this happens over time and is normal, and the baby is creamy white. If tugged gently the old mother will fall free of the baby scoby. Once a scoby has turned this very dark brown it is old and can no longer brew (this can take 6 months to 1 year).

How many times can I reuse a SCOBY? ›

Put simply, kombucha SCOBYs can be reused for many years. Realistically, however, you simply won't need it to last that long. Your SCOBY grows and divides with each batch of kombucha, so you will constantly be growing new SCOBYs. Simply remove the older layers and transfer the new layers to your next batch.

Is my SCOBY supposed to float? ›

As mentioned earlier, each SCOBY is one of a kind when it comes to density, and thickness, which determines whether it will float or sink. Its weight, shape, and structure all influence its buoyancy. It's worth noting that no two SCOBYs are the same, so some will float while others sink in your fermenting tea.

What does newly forming SCOBY look like? ›

When forming, the baby SCOBY initially looks like a clear and kind of gelatinous film/layer. It will gradually fill in more and more, becoming more opaque and less “jelly” looking. If your SCOBY is looking more like a jelly than a creamy white disc, you likely just need to leave your brew for a bit longer.

How do I know my SCOBY is ready? ›

When the scoby is about 1/4-inch thick, it's ready to be used to make kombucha tea — depending on the temperature and conditions in your kitchen, this might take anywhere from 1 to 4 weeks.

How thick should a new SCOBY be? ›

Baby Scobies

(don't worry if mother and baby are fused together just leave them joined and your mother scoby will get bigger and bigger!) You then gently place the new scoby in your next batch. Keep doing this until your baby scoby is about ½ to ¾ inch thick. It is then ready to be used independently to brew with.

References

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