How to Tell if Kombucha Is Bad?

The appearance, smell, and taste of kombucha can change as the drink ferments. If the smell or taste changes, it’s probably wrong. If it’s still odorless when placed in a glass, it may be okay to re-use it. However, if you notice mold or bacteria, throw it away. The good news is that kombucha can be fermented again. Store-bought kombucha may be better than homemade if you’re unsure.

Store-bought kombucha will likely contain added preservatives and processing to extend its shelf life. Make sure to read the guide provided with your kombucha and label the bottle correctly. Keep your kombucha in an airtight container and store it in a cool, dark place.

How to Tell If Kombucha is Bad

The first sign of kombucha going wrong is a decrease in its flavor. If it’s been out of the fridge for a day or two, it will lose its carbonation. Eventually, the flavor will turn super-acidic, and the live probiotics will be gone. This is usually not an immediate warning that your kombucha has gone wrong. However, it is essential to drink kombucha within a day of opening it.

Inspect the SCOBY. If it’s bumpy and contains clumps of yeast, it’s probably healthy. Otherwise, it’s either too old, or the SCOBY may have been started with too hot tea. These two are separate signs of sour kombucha. It’s essential to keep your SCOBY clean to prevent cross-contamination. So, make sure to look for these three things when inspecting your kombucha:

How to Tell if Kombucha Is Bad?

Because it’s a fermented product, it’s pretty acidic. Any microorganism that isn’t already present will struggle to survive and grow in such an environment. As a result, the beverage keeps and does not spoil quickly for a long time. Things may, however, go wrong in rare instances. The presence of mold is the first and most apparent sign of spoilage. It’s a rare occurrence with homemade kombucha or an older batch that developed its baby SCOBY (more on that below) on top, and mold began to grow on it. If you find mold, toss it out.


Another sign of lousy kombucha is a strong odor. The odor could be mold or fermentation of vinegar. It’s not harmful to taste a small sip, but you should avoid drinking it if it has a strong smell. If it smells too sour, it isn’t good. In this case, refrigerating is a good idea because it slows down the fermentation process and prevents acid formation. The second possibility is that your kombucha has developed a vinegary flavor ([NE]), and you no longer find it enjoyable to drink. This is a natural result of fermentation and occurs in kombucha that has been refrigerated for months or sitting on the counter for a few weeks.


The next sign of kombucha that has gone bad is mold. Although this is a rare occurrence, it should be discarded. However, if the mold is found on the bottle cap, you should throw out the entire bottle. You should also avoid drinking any kombucha after the best before date.


It should last for months as long as it’s not fermented to taste sour; it should last for months. The alcohol content is another major factor to consider when determining if kombucha is terrible. Drinking kombucha over 1% ABV is extremely dangerous for pregnant women and children. Homemade kombucha is unlikely to be tested for alcohol, so it’s best to trust your instincts. Your body will tell you whether a drink is good or bad. If your body reacts badly, don’t drink it.

How Long Does Kombucha Last?

Depending on your brand, kombucha can last from a few months to a year. Most kombuchas keep their flavor for a few weeks after their expiration date, but they eventually become acidic.

I’m afraid I can’t give you a specific timeline because it depends on the producer. It usually lasts anywhere from a few months to a year ([CK]). The industry standard appears to be six months from the time of bottling ([CK][RK]). As you may know, kombucha does not quickly go wrong, so that it won’t go bad after a week or two after the expiration date on the label. The fermentation process in kombucha is ongoing, similar to that in unpasteurized sauerkraut, and the flavor changes gradually. So it’s not like it’ll be fine one day and then be terrible the following day.

However, after a while, you’ll notice that the flavor no longer appeals to you, and it’s time to either discard it or put it to other uses ([NE]). It is a matter of personal preference, and there are no hard and fast rules if it happens near the best-by date or a few weeks (or months) after it. Furthermore, this period varies between batches, so this period will change even if you’re a brand loyalist.

How to Store Kombucha?

The recommended storage method for an unopened bottle varies (again) between producers. Some manufacturers recommend keeping it at room temperature ([CK]), while others recommend refrigeration ([GTS][RK][NE]). Keep it in the fridge if you’re not sure.

Once you’ve opened the bottle, could you put it in the fridge? The cold temperature slows the fermentation process, preventing it from becoming too acidic too quickly. If you prefer your kombucha to be less acidic, keep it refrigerated, like dairy products like kefir or yogurt.

When storing the bottles, make sure they are kept upright rather than on their sides ([GTS]). Otherwise, you may need to clean your refrigerator after some liquid has leaked from the bottle.

Why Isn’t My Kombucha Fizzy?

If you’ve noticed that your once-effervescent kombucha has gone flat, there’s a reason for it! It all boils down to a science lesson.

The brew sits at room temperature while being made into kombucha. This allows live yeast to feed on the sugar used to sweeten the tea, allowing them to thrive. As the yeast consumes the sugar, carbon dioxide bubbles form, giving your kombucha that familiar bubbly sensation.

If you’re wondering why your kombucha isn’t fizzy, read on. This query may have arisen after taking a bottle from the refrigerator. The yeasts may go dormant, and the carbonation may settle due to the cold temperatures. You can often reactivate the internal consumption process by sealing the bottle and leaving it out for a few hours.

What Are the Side Effects of Consume Too Much Kombucha?

The following are five potential adverse effects of consuming too much kombucha.

1. May Lead to Excess Calorie Consumption

Kombucha comes in various flavors, and some are minimal in calories, while others include 120 calories per bottle. Drinking kombucha once in a while isn’t affected your waistline, but drinking it every day could lead to excessive calorie consumption and weight gain.

People who consume high-calorie drinks regularly are more likely to be overweight or obese than those who do not. This is because liquid calories are easier to swallow and are less filling than solid-food calories. Furthermore, calorie-dense beverages frequently replace more satisfying, nutritious snacks that might keep you feeling fuller for more extended periods.

2. May Cause Bloating and Digestive Distress

Due to its probiotics, or helpful bacteria, kombucha has benefited digestive health. However, consuming too much may result in negative consequences. Too much kombucha might induce bloating because it is carbonated. Carbon dioxide (CO2) is released into the digestive system when carbonated beverages are consumed, inducing bloating and gas.

Kombucha also contains FODMAPs, which are certain carbohydrates that can cause digestive pain in some people, notably those with IBS. Finally, drinking too much kombucha can increase sugar consumption, which can cause water to be pulled into your intestines, resulting in diarrhea. As a result, consuming too much kombucha may cause bloating, gas, and diarrhea in some people.

3. May Contain Excess Amounts of Added Sugar

Many kombucha drinks are sweetened with fruit juice or cane sugar to make the product more appealing to customers. While this may enhance the flavor of kombucha, it also raises the sugar content of the beverage when ingested in excess; added sugars, particularly those found in sugar-sweetened beverages, can harm your health. Sugar-sweetened beverages, for example, have been related to higher rates of diabetes, obesity, fatty liver, and heart disease.

One serving of kombucha can contain up to 28 grams of sugar, which is the equivalent of 7 teaspoons of sugar, depending on the brand (19). Although some kombucha brands are heavy in sugar, other kombucha products are better alternatives. When shopping for kombucha, seek drinks with less than 4 grams of sugar per serving to limit your added sugar intake.

4. Dangerous for Certain People

While kombucha is generally safe, it can have serious adverse effects on some people. Because kombucha is unpasteurized and contains a combination of bacteria and yeasts, it might encourage the growth of opportunistic microorganisms, which can cause infections in some people. Drinking kombucha, for example, can cause significant difficulties in persons with compromised immune systems, such as those who have cancer, kidney illness, or HIV.

Although rare, severe allergic responses, acidosis, and liver issues have been documented as consuming potentially tainted kombucha. Because kombucha is unpasteurized and includes small amounts of caffeine and alcohol, it is not recommended for pregnant or breastfeeding mothers.

5. Could Lead to Excess Caffeine Consumption

Black or green tea, which contains caffeine, is commonly used to make kombucha. Although kombucha has significantly less caffeine than typically brewed tea, consuming too much caffeine from kombucha can be dangerous.

For example, each 8-ounce (240-ml) serving of GT’s Kombucha includes 8 to 14 mg of caffeine. While this is a minor quantity compared to the 47 mg of caffeine in one cup of brewed black tea, persons who are sensitive to caffeine may have side effects if they consume too much kombucha. When drinking too much kombucha, people who are sensitive to the effects of caffeine may feel anxious or jittery. Additionally, consuming kombucha close to bedtime may create sleep disturbances.


When storing homemade kombucha, it’s best to store it in the fridge. Store-bought kombucha must be refrigerated, and you’ll want to store it in the refrigerator once the fermentation process is complete. Room-temperature kombucha will begin to turn into vinegar. However, if you’re storing homemade kombucha, you should transfer it to the fridge after it ferments.

This way, it’ll keep its flavor. Mold-free kombucha is safe to consume, but throw it out if you notice mold in your kombucha! While it’s rare, you’ll want to avoid mold if you find it. However, if you notice any mold, it’s probably a product of over-fermentation. If it’s still suitable for cooking or drinking, you can always use it for other purposes.