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Top 10 Questions

Q: My culture looks weird, is it okay?


A: Yes! While mold and other abnormalities can occur during brewing, it's truly quite rare. However, let's face it, kombucha cultures look strange and oftentimes it is confusing to tell what is happening during those initial few brews. First, don't stress about mold—most likely what you are seeing in your brew is air bubbles or yeast. The yeast looks especially odd because it can appear blue, green, even pink and orange sitting underneath the iridescent culture that grows in across the top during the first few days of brewing.

Check out our gallery of healthy and unhealthy cultures below and see if your culture looks like any of these. If you're still not certain your brew is progressing as it should, please send an email with a picture to questions@thekombuchashop.com and we'll help troubleshoot!

Healthy Cultures

A healthy culture may have brown, stringy or blob-like debris attached to it. It can be bumpy or smooth, and have clear dots or bubbles. When you drop your new culture into the brew jar, it can sink to the bottom, float in the middle, or float on top—all location are just fine and will ferment your kombucha just the same. 


Unhealthy Cultures

Similar to molds you would see on bread or cheese, an unhealthy culture will develop fuzzy blue, green, or white mold. Again, this is rare, and is usually caused by accidental inoculation from airborne spores in the house. Or, if a culture is incorrectly stored without enough starter liquid to rest in (and thus exposed to oxygen for a prolonged period of time instead of resting happily in plenty of liquid). If you're still unsure if you have mold present, please send us a picture at questions@thekombuchashop.com and we'll get it sorted out!



Q: My house is cooler. How can I keep my brew warm?


A:  We are located in Madison, WI so we're experts at brewing in cold temps! Here are some of our top tips for keeping your brew warm:

1) In the winter, we prefer to move our jars up to a high shelf in a warm room, like on top of cupboards or a tall bookshelf. Sometimes this means moving the brew jar upstairs, where it tends to be warmer (if you have a multi-story home). 

2) If your brew jar is resting on a cold countertop, place a book, towel, or cutting board underneath it for insulation.

3) If taking those steps doesn't keep the temperature above 68 degrees, we highly recommend picking up one of our custom heating wraps. We designed them exclusively for kombucha home fermentation. With four temperature settings, it will keep your brew in the perfect range year round! 

Additionally, you may be wondering about keeping your bottles warm for the second fermentation. You'll want to store your bottles somewhere warm during the second fermentation (mid 70's if possible) to ensure yeast is actually fermenting the sugars in the bottle and creating that much desired carbonation. If you can't keep your bottles consistently above 70 degrees, you won't create carbonation. If you don't have a warm spot in your home, we recommend placing your bottles in a line on your counter and weaving our kombucha heating wrap through them. They'll ferment and carbonate much quicker, typically 2 days.

Q: What is the importance of temperature when brewing?


A: It's important to keep your brew jar as close to 74-80 degrees as possible, that is when the culture produces the most balanced ratio of yeast to bacteria. As you'll soon discover, kombucha brewing is all about finding balance. 

Colder Temps:

It's fine if your brew drops as low as 68 degrees. Just know it may take three weeks to fully ferment. However, if it goes below 68 degrees for an extended period of time it can be more prone to develop mold, as the bacteria and yeasts will start to go to sleep. So try to keep it 68 or above. 

Warmer Temps:

If your home is very warm in the summer time, it's important to keep your brew jars somewhere cooler so they won't get too warm. It's best to not let your brewing jars stay above 82 to 84 degrees for too long or your yeasts will begin to overpopulate and throw your brew out of whack. Additionally, your fermentation will happen too quickly and you're likely to end up with kombucha vinegar. 

Q: My kombucha tastes great, but it's not very fizzy, what can I do to make it more carbonated?


A: Carbonation is created when yeast converts sugar into C02 and alcohol. If you want to increase the C02 (fizz), there are several things you can do to increase the carbonation during both the first and second fermentation.

First, let the first fermentation brew for longer. Allowing your initial brew to go for at least 14 days will strengthen all of the activity in your current brew and create stronger starter tea moving forward (making your future batches better). At the end of your first fermentation, there should be at least a small amount of natural carbonation that has built up. 

If you'd rather only do the initial brew for 9 -14 days but still want some good carbonation, then bottling for a second fermentation is a must!

Try these second fermentation steps to get your kombucha bubbly:

1) Fill your kombucha bottles closer to the top. Leaving no more than an inch of space. By reducing the amount of oxygen present in the bottle, more C02 is dissolved into the kombucha.

2) Increase the sugar content in your second fermentation. Either add fruit or fruit juice to each of your bottles (if you've already tried this and it didn't make it more carbonated, try adding 1 tsp sugar to each bottle).

3) Allow the second fermentation to go longer, try 4-7 days. Do note, you will need to start burping the bottles once a day or so after about 4 days of fermenting to ensure they don't explode (it's quite rare, but it happens). Simply open each bottle slowly to release the C02 and recap. 

4) Your second fermentation should be at room temperature. As soon as you place a bottle in the refrigerator, fermentation, and therefore, C02 creation, will cease. If you like it bubbly, don't place it in the refrigerator until it has reached the carbonation level you enjoy.

5) If you are using old kombucha bottles from the store, try placing a small square of parchment paper underneath the cap to get a tighter seal. Bottles with a long neck that use swing top or poly cone tops are the best bottle type for building and holding carbonation. 

6) Know that your kombucha will change from brew to brew based on a variety of factors including temperature, the length of brewing, the tea used, etc., and each brew may not always reach the highly carbonated levels of commercial kombucha because commercial breweries add artificial CO2 during bottling.

7) Speaking of adding CO2, if your kombucha seems flat and you want some added fizz in a hurry, you can always add sparkling (soda) water to your kombucha. Or, use an at-home carbonator, such as a Soda Stream, to inject CO2 directly into your kombucha.

Q: I finished my first brew, and now I have two cultures. Should I use the old or the new one for my next brew?

A: You can use both! We recommend keeping anywhere between 1-3 cultures in your brew at a time. An old culture is only ready to be retired after 5-7 brews, or if it turns a really dark brown and can be ripped apart easily. Oftentimes, your old and new culture will form into one large culture which is great as well. If your cultures continue to grow onto each other, be sure to keep the whole culture under 2 inches thick (height). Simply peel off the oldest layer to accomplish this, or cut it in half. It's important not let it get too big (over 2 inches thick) as it will start to inhibit the flow of oxygen to your brew, and also cause the sugar to be processed too quickly, throwing off the proper yeast/bacteria ratio. 


Q: I have been brewing for a few days and my culture suddenly sank to the bottom of the jar. Is that okay?

A: Yes! That is fine. There was likely a fluctuation in temperature and it caused the culture to sink. It can sink, it can float on top, or sit in the middle—it's fermenting all the same. Your culture is still working hard to produce a new culture that will cover the surface of your brew. Evidence of this new culture should appear by Day 7. It can take up to 2 weeks for a new culture to grow in on the top. 


Q: I'm on Day 7 of brewing and my new scoby is pretty thin. Is this normal?

A: For Day 7 at 75 degrees, we would expect a culture to be about a quarter of an inch thick. However, the majority of scoby growth tends to happen between Days 7-21, so no need to worry just yet. Make sure that the culture is in the proper temperature range (68-84 degrees) as being too cold or hot can inhibit scoby growth.

Also, keep in mind that the first time brewing with the kit is usually the slowest.  After a couple of brews, the culture and starter tea begin to establish themselves in their new environment and fermentation happens faster.

If, after a few more brews, your culture isn't growing in well, or your kombucha tastes off, then you may need a new culture/starter tea pouch. Certainly keep and set aside your current culture and starter tea for future use (at the very least you can get two batches going simultaneously) but with a new starter tea/culture pouch you will be able to determine if the culture/starter tea is the problem, or if something else is amiss. 

Q: How do I store the culture when I want to take a break in between brews?

A: We recommend storing it on your countertop, in a glass jar (the 1 gallon brew jar works well), placed in at least 1 to 2 cups of liquid kombucha starter tea (your previously brewed kombucha) and covered with the cotton cloth and rubber band. You can store it like this for up to 4 weeks, at which point it will likely need to be fed. To feed your culture, steep 1 teaspoon loose leaf tea (or 1 tea bag) in 1 cup of hot water. Dissolve 1/4 cup of sugar in the tea. Allow the sweet tea to cool to room temperature and add it to the jar housing your culture & starter tea. Repeat this process every 4 weeks to ensure the health of your culture between brewing.

Q: My culture has brown stringy debris attached to it. What is that?


A: That's the yeast! And it's a great sign that you have a lot of good fermentation going on. Yeast is a good thing :)

Q: How long can I leave the culture in its plastic bag before brewing?


A: We recommend brewing within 2 to 3 weeks of arrival—the sooner you brew, the fresher it is and the better your kombucha will be. However, our culture pouches are shelf-stable, at room temperature, for many months typically even past the "brew by" date listed on the pouch. If you do plan to store the culture in its pouch for an extended period of time before brewing, we recommend doing so in a cool pantry at, or under, 70 degrees.