Top 7 Signs of a Perfectly Healthy Kombucha Brew

How Do I Know For Sure That My Kombucha Brew Is Healthy

Good question.

New kombucha brewers who are starting out often wonder if their brew and culture is healthy. The microbial makeup of the SCOBY culture can raise concern in first time brewers, who wonder if outside bacteria have invaded, or if the existing bacteria may have morphed!

As SCOBYs can take on all sorts of appearances, from pearly white perfection to soggy and gray with brown strings hanging off – not to mention those thick bumpy ones with holes – the look of one’s SCOBY is not usually the most encouraging sight as a newbie brewer wondering if everything is on the right track.

Who knows, what if you are scientifically rotting tea and calling it your home brewed kombucha!

Fortunately, even though the looks of your SCOBY are not always a big help in gauging its health, there are other factors which you can check to make certain that everything is on the right track.

While you may not need to look for ALL of these signs, a few of them are good indications things are going well.

How to Tell if Your Culture and Kombucha is Healthy

We give you 7 signs that indicate your Kombucha brew is healthy and your SCOBYs are doing their thing right.

1. A Balance of Cellulose & Brown Yeast Strands

As SCOBY stands for Symbiotic Colony of Bacteria and Yeasts, one of the key elements to good SCOBY health is the balance between the yeasts and the bacteria. This is one thing which can be indicated by the appearance of your SCOBY. The bacteria are not visible to the naked eye, but the yeasts are made visible by the brown strings that hang off the bottom of the SCOBY, float free, or settle at the bottom of the brewing vessel. The bacteria are the ones responsible for manufacturing the cellulose body of the SCOBY culture. A thick tight SCOBY body, combined with reasonable amounts of yeast strands on it or hanging off it are a sign of a healthy culture whose microbes are in balance and thriving.

2. The Kombucha Smell’s Right

The smell of your brewing kombucha is one of the best indicators, not only of the health of the brew, but it can also let you know how far along your batch is and how strong it is getting. For more info on how to tell if you kombucha is ready, you can also read When is My Kombucha Done Fermenting. Kombucha has a distinct smell, which is a balance between sweet/sour. The longer the brew is left to ferment the sharper and more sour it will smell as the sugar gets eaten up and the ph level goes down. Anything along this change from sweet to sour is quite distinguishable, and indicates that fermentation is taking place and all should be well. Strange or off-putting smells are usually a sign of some sort of problem with your culture.

3. The .Ph level 

As fermentation takes place in your brewing batch of kombucha the ph will drop. The brew should always start off with a slightly acidic ph. This is because an acidic solution is more resistant to mold or invasion by pathogenic foreign bacteria. That is why kombucha making recipes usually call for either an addition of starter liquid (mature kombucha) or spirit vinegar. Adding starter liquid or spirit vinegar ensures that your brew is protected from the start, and no foreign microbes can take hold in the interim while fermentation is still getting on the go. Finished kombucha tea should have a Ph of between 3.2 and 2.5. If you wish to test this, you can purchase Ph strips or an electronic Ph meter from your pharmacy or online. The reason why an increasingly acidic ph level is indicative of a healthy brew is because this shows that fermentation is taking place successfully, and gives you the added benefit of knowing that the more acidic your brew is getting the less chance there is of it getting contaminated by foreign or unwanted microbes.

4. There’s a Baby in the Brew

If you are finding baby SCOBY layers forming on the surface of your brewing kombucha, this is a sign of culture health. The formation of new SCOBY cellulose layers indicates that the microbes are in balance, conditions/ingredients are right, and they are proliferating!

5. Thickening Existing SCOBY Cultures

Sometimes instead of baby SCOBY layers forming on the very surface of your brews you will only see a thickening of your existing culture. This is actually the same thing, only circumstances are so that the new layer is close to the brewing culture and ends up attaching itself to the top of it. This of course will result in a steady thickening of your kombucha SCOBY with each successive brew, and is also a sign that the microbes are happy, balanced and thriving.

6. The Taste Test

The taste of your ready to drink fermented kombucha is another result of healthy SCOBYS. Brews which taste strange or unappetizing can easily be a result of a compromised SCOBY culture. Do not drink any batches which are unpleasant flavor wise. Kombucha is meant to be enjoyed, not grimaced down, and an off taste could mean that fermentation has not taken place properly.

7. The Tea Changes Color

If you are using black or some other dark tea to brew with, usually you will see that as fermentation takes place the tea will start to lighten in colour. This is because the tannins are being converted and consumed by the yeasts and bacteria. If you see that your brewing kombucha lightens decidedly in colour, this means that the microbes are doing their job and are healthy and happy.

It’s All About the SCOBY Microbe Balance

No home brewer wants an unhealthy kombucha culture or sub-fermented brew. The main cause of SCOBY ill health is usually an imbalance between the yeasts and the bacteria. Both of these populations needs to be at the right level, otherwise one will dominate the other. As time passes, the SCOBY balance often swings to a dominance of the yeasts. This is particularly true in warm temperatures. If you think that you might be experiencing this, have a look at What to Do If There is Too Much Fizz in My Kombucha.

However if your culture is newly purchased of just come out of storage/hibernation then it is quite likely that the bacteria have the upper hand. For tips on how to encourage the yeast and bring your culture back into balance, have a look at What to Do If There is No Carbonation (Fizz) in My Kombucha.

There are also other factors which can be influencing your SCOBY and possibly damage it. These include, contaminants in the air, the wrong kind of water, or an invading bacteria/insect/mold.