What to Do If There is No Carbonation (Fizz) in My Kombucha

Where’s My Kombucha Fizz!

Besides sweetness and flavour, one of the most pleasant taste sensations of Kombucha is its’ slightly effervescent quality. Kombucha makers claim that an absence of carbonation is not a bad sign, and it does not necessarily mean that the fermentation process has not taken place effectively. As long as your SCOBY is thick and healthy at the end of the ferment, then there is nothing to worry about. (If you are unsure if this is the case, check out What Does A Healthy Kombucha SCOBY Look Like?)

However, if you enjoy the fizzy effect – and are struggling to achieve it – there are a few of the main methods of upping the carbonation in your Kombucha. But first, here is some basic info on the science behind it which will help you to better understand what’s going on inside your brew.

Yeasts Versus Bacteria – The Composition of the SCOBY

The Kombucha SCOBY is made up in part by two types of organisms: Yeast and bacteria. The yeast species present in the SCOBY are responsible for the carbonation part of the fermentation process. They digest the sugars in your Kombucha brew, letting off carbon dioxide as they go. This is what causes the bubbles and carbonation, much the same as in the brewing of beer.

A healthy balance between the yeast population and the bacteria population within the SCOBY is very important for maintaining SCOBY health, and good results from your ferments. Imbalances are usually more often caused by an overabundance of yeasts, rather than bacteria, therefore caution should be exercised when encouraging action of the yeast population in your SCOBY.

Catering To The Yeasts

Yeast feeds on sugars, increases activity in warmer temperatures (e.g. leaving bread to rise in the oven or in the sun), and can continue to work with or without direct exposure to air.

It is possible to increase carbonation by providing the yeasts with extra sugar at the correct time, warmer temperatures, more oxygen during the initial stages of fermentation, and by making sure that your starter is properly populated with yeasts. However, remember to bear in mind that this might cause an imbalance in the SCOBY between yeasts and bacterium populations.

There are also other methods to increase fermentation which do not affect the SCOBY, which I will outline shortly. If you are worried about increasing the yeast proportion in your SCOBY and would rather implement these, feel free to move on down to “How to Increase Carbonation Without Increasing the Yeasts”.

How to Increase The Yeast To Bacteria Ratio for More Fizz

If you want to increase the yeast component of the SCOBY here are a few different methods which if applied in moderation can do so without increasing it to the point that it is detrimental to the SCOBY. These five methods will increase the yeast levels (affecting the yeast to bacteria ratio) in the Kombucha which will in turn increase the carbonation.

1. Use the Starter from the Bottom

For your starter, use liquid from the bottom of the previous Kombucha batch. This will contain a higher amount of yeasts than that taken from the top. You might be able to see some brownish blobs and strands floating in the liquid – these are the free floating yeasts. Note that if you are taking starter from your SCOBY hotel, rather than from your previous batch, the liquid at the bottom of the hotel will probably also contain dead material, which can give your new batch an slightly rotten taste. Changing the tea in your SCOBY hotel regularly will ensure clean starter liquid.

2. Double the starter

Take double the usual amount –  approximately 20% rather than 10% – of the starter. You can do this until carbonation increases, and then reduce to 10% again.

3. Air the Starter First 

Leaving the starter for 3+ days in the open covered with paper towel, cloth, or panty hose will allow airborne strains of yeasts to colonise it as well. This can be of benefit, as these varieties might be dormant or absent from your initial SCOBY. Different types of yeast produce higher amounts of carbon dioxide, therefore doing this might be advantageous, as though one does not want an imbalance of yeasts to bacteria, one does want to have all the right species present.

4. Raise the Brewing Temperature

If possible, start your batch at 75 to 85 degrees Fahrenheit to assist the yeast populations. Warmer brewing temperatures (i.e. the room temperature the container is placed in) will increase the yeast activity levels and thus increase carbonation.

5. Increase Sugar Content

While too much sugar present at the start of the fermentation can actually inhibit the production of carbon dioxide and encourage the production of alcohol instead, adding sugar once the yeasts have developed in the brew does the opposite. This is because the yeasts now can process additional fuel and continue their process of carbonation. The key is to do the adding at the right time. Adding of sugar should be done roughly halfway through the process for best results.

6. Decrease the Sugar Content

While adding sugar once the yeasts have multiplied can increase carbonation, too much at the start of the brewing process can inhibit it. So if you have been increasing the sugar in your sweet tea brew in your brewing attempts and not having a good amount of fizz developing, then  take it down a notch and reduce the amount of sugar you add and test — you may find the fizz levels increase this time around.

How to Increase Carbonation Without Increasing the Yeasts

If you are wishing to increase carbonation and get a fizzier brew without affecting the yeast to bacteria ratio of your SCOBY, there are some very effective ways to do so.

1. Do Secondary Fermentation

If you have made a few batches but wish for more carbonation, or notice a drop, then consider the other factors which can affect carbonation. Make sure that your tea is strong enough, the right type, there is enough air etc. And then do a double ferment! Many Kombucha brewers make this a standard practice, as it enhances the flavor, carbonation, and increases nutrient content. What’s not to like?

Probably the simplest and safest (when concerning SCOBY health) way of maximizing carbonation in you brew is by doing a second fermentation. During the first ferment not sealing in the carbonation (there is no sealing of the Kombucha during first ferment phase), a lot of the bubbles and carbon dioxide produced by the yeasts escape from the tea; much the same as a soda goes flat once opened, only in this case the bubbles are escaping as they are being produced.

IF YOU HAVE NOT BEEN DOING A SECOND FERMENT AND YOU WANT FIZZ, START DOING IT! You can’t get a good fizz without a second ferment!

To do a second ferment you have to bottle up your brew and instead of refrigerating, leave well-sealed under room temperature conditions. The fermentation will continue, and carbonation will build up inside the bottles, instead of escaping as in the first stage.

On average, the second ferment can be left for 48 – 72 hrs. However, remember that as the carbonation continues pressure is increasing within the bottles. Before doing a second ferment it might be a good idea to read How to Prevent Your Kombucha Bottles from Exploding. There is nothing more irritating that cleaning up a big mess when all one wants to do is get on with your Kombucha making!

Besides adding carbonation, doing a second ferment also increases the nutrient content of Kombucha. To find out the added health benefits of doing a second fermentation you can read How To Make Second Ferment Kombucha (And Why You Absolutely Should)

2. Add in Something Sweet During Second Ferment

A great quick fix for added fizz is to add a little sugar or some other form of sweetening just before bottling. This is effect whether doing a second fermentation or not, just be careful not to overdo it, as the pressure can sure build up! This pre-bottling addition can either be plain old sugar, fruit juice, or small quantities of fruit – anything with  a source of glucose (sugar molecules). If you have added fruit to the second ferment (which, most people do), you can also add a little bit of sugar for an extra fizz boost.

Or you can try adding a fruit that has a tendency to give an extra kick to the carbonation. For example, I find that a few slices of ginger does the trick nicely, and lends your finished Kombucha a ginger beer-ish flavor!

3. Temperature control

Start your batch at 82 degrees Fahrenheit if you can, and maintain it there until bubble show up, which means that the yeasts have multiplied. Then reduce to 72-75 degrees for the rest of the fermentation to ensure that the balance towards yeast does not shift.

4. Strengthen Your Tea

To weak of a brew of tea can inhibit growth and activity of the yeasts, as they feed on nutrients in the tea. If you think that your tea is looking weak, make your new batch stronger and see if there is an improvement in carbonation. Or try using kombucha from your SCOBY hotel as starter for your next batch — it’s more packed with yeast than regular starter.

5. Pick the RIGHT Type Of Tea

Using tea other than black, green, white or oolong tea can also cause a drop in carbonation, as there are specific nutrients present in these teas which the yeasts feed on. To remedy this, try using one of the regular teas.

Typically, ‘black’ tea is the standard recommended tea, though green tea should be perfectly fine (read the difference between green vs black tea for Kombucha). You shouldn’t have any problems using our recommended tea types, but if you do notice a lack of fizz, try switching to a black (organic and unflavored) tea. Or you can mix teas, using a 60 percent black tea and 50 percent other tea blend — this allows you to combine different tea flavors without affecting the SCOBY health and thus the yeast production (and carbonation production).

The types of Tea used for making Kombucha do play a key role in how carbonated the brew gets and the end taste.

6. Ensure Enough Oxygen During First Ferment

Another thing that can inhibit the yeasts to produce carbonation can be lack of oxygen during the initial phase of fermentation. While yeasts do not need oxygen to survive, if there is not enough oxygen present, and too much sugar for the yeast population at that time, they will produce alcohol rather carbon dioxide.

When doing a second ferment, if no sugar is added the yeasts continue to carbonate the liquid, as by then their numbers have grown sufficiently. However, if additional sugar is added before the second ferment, alcohol production will occur. For more in this read our article how To Increase Alcohol Content Of Kombucha Tea.

Increase Surface Area of Brewing Container: If you are using containers with narrow openings, this will probably reduce the amount of air available to the SCOBY, and it might a good idea to switch to jars with wider mouths. Surface Area plays a key role in your fermentation time…and how your brew ultimately tastes.

Allowing More Air Through: Too dense of a cloth covering can also prevent enough oxygen reaching the Kombucha brew. Check to make sure that the material you are using as a cover is not too dense to allow enough oxygen through.

Whisking: Whisking the unfermented tea before inserting your SCOBY also exposes the yeasts to more oxygen, and encourages them to produce more carbonation.

7. Make Sure You Use a Sealed Latch Wine Bottle for Second Fermentation

If you are doing a second ferment (and really, you SHOULD be if you want any carbonation at all), make SURE you use a narrow wine-style bottle  with a sealed latch.

Like this:

Using THIS style bottle gives you a better, more carbonated ferment over say a canning jar or a regular mason jar.

More Reasons Why There is No Fizz

Before jumping in and implementing all the things outlined above in one shot, think about your process and gauge what you feel might be the cause of decreased carbonation.

Is Your SCOBY New?

If you have purchased a SCOBY starter recently and this is only your first or second batch, then it is quite possible that the yeasts in SCOBY are still a bit dormant. It is also then likely that the airborne strains have not had a chance to colonize your SCOBY. If this is the case, then encouraging the yeast component of the SCOBY is not a bad idea.

Is Your SCOBY dehydrated

If you bought a dehydrated SCOBY, you’ll need to properly reactivate it and it will take a few brewing cycles before such a SCOBY will function normally (indeed, we do not recommend buying dehydrated SCOBYs — you are much better off buying an active SCOBY in starter rather than a dried out one). If your new SCOBY is dehydrated and you are trying your first or second brew — you may either need to do a few more brewing cycles to get your SCOBY working properly, or your SCOBY may have health problems and you’ll need to replace

Is Your SCOBY healthy

Another reason for low fizz / no carbonation is that your SCOBY is dying or unhealthy. It could be the SCOBY is simply too old (the mother will last for months, but you will need to replace it eventually with a fresh baby scoby) and dying or the SCOBY has health problems. Either way, you should replace that SCOBY with a brand new baby one (which if you have been making Kombucha for a few cycles, you should already have via the baby scobys). Take a look at what a healthy scoby should look like.