Q: My culture looks wierd, 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 (click on a picture to enlarge it) 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 firstname.lastname@example.org and we're happy to give our opinion!
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 sit on top - all locations are just fine and will ferment your kombucha just the same.
Similar to molds you would see on bread or cheese, an unhealthy culture will develop fuzzy blue, green, or white mold. Again, this is very rare, and is usually caused by accidental inoculation from airborne spores in the house or if a culture is incorrectly stored without enough starter tea to rest in (and thus exposed to oxygen for a prolonged period of time instead of resting happily in plenty of liquid kombucha). If you're still unsure if you have mold present, please send us a picture at email@example.com and we'll give you our opinion!
Q: What is the importance of temperature when brewing?
A: It's important to keep your brew jar as close to 74-76 degrees as possible, as that is when the culture produces the most balanced ratio of yeast to bacteria. As you'll soon find, kombucha brewing is all about finding balance.
It's fine if your brew drops as low as 68 degrees. 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. The colder it is, the longer it will take to brew. And vice versa, the warmer it is, the faster it brews. If you live in a cold climate or keep your house cooler, we highly recommend investing in a Kombucha Heating Wrap - it will keep your brew jar in the perfect temperature range. We use them year round in Madison, WI!
If your home is very warm in the summer time, its important to keep your brew jars somewhere cooler they won't get too warm. It's best to not let your brewing jars stay above 84 degrees for too long or your yeasts will begin to overpopulate and throw your brew out of whack.
Be sure to keep any heating methods like a heating pad in check. If leaving your heating element on all the time is keeping the temperature too warm, simply turn it on a for a few hours a day and wrap a towel around it to insulate.
Q: How hot is too hot for a kombucha culture?
A: A culture can hit 95-100 degrees for a short time and survive just fine (like during shipping). Optimally, you want to be able to keep it consistently in the mid 70's, or upper 70's at the most. If the temperature goes above 88 for more than a few hours, the bacteria get out of control and throw off the brew. That is why our temperature gauge stops reading above 88—because the temperature really shouldn't ever be any higher than that.
Q: Can I store my culture in the refrigerator?
A: You can store kombucha cultures in the refrigerator for a short period of time; roughly 2 weeks is all we recommend. Storing in the refrigerator is a risk—the yeasts and bacteria go dormant in the cold temperatures and can have a hard time bouncing back to full brewing strength after they have been chilled. Sleepy yeast and bacteria leave your brew more at risk for developing mold.
If you do refrigerate your culture, store it in a glass jar in at least 1 to 2 cups of starter tea with a lid. The night before you would like to brew again, simply remove it from the refrigerator, place on your countertop and cover with a cotton cloth and rubber band. Allow the culture to return to room temperature over night before brewing the next day. If it has been refrigerated for a period longer than 2 weeks, feed your culture the night before brewing with it. (To feed your culture, make one cup of hot caffeinated tea, and dissolve 1/3 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.)
Q: I finished my first brew, and I now 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 ready to be retired after 5 to 10 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). Why? Because if your culture is covering the entire top surface of your brew, and is over 2 inches thick, 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. To reduce the thickness of a culture, simply peel off the oldest layer and discard, or simply cut it in half, like a half moon shape, and plop it in your brew.
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 don't have the whole cup of starter liquid left form my previous batch. Can I use less?
A: A half a cup of starter liquid is the smallest amount you can use to brew one gallon with. If you use only 1/2 cup starter, we recommend brewing closer to 3/4 of a gallon. When you use a smaller amount of starter liquid, expect it to take a little more time to brew, typically 3 to 5 days longer than usual.
Q: I forgot to save enough brewed kombucha (starter liquid) to store my culture in. Can I use kombucha that has been in the refrigerator?
A: If your kombucha that is stored in the fridge is plain, then yes! As long as you didn't add any flavoring to it, it will be no problem to pull some out of the fridge, place it in a small jar with the culture (covering the jar with a cotton cover) and set it out on your counter for a night or two to warm back up. Once the starter tea has fully come back to room temp and "woken back up" so to speak, then it should be great to brew with!
Q: Can I add in fruit or fruit juice during the first fermentation?
A: We do not recommend adding in fruit or fruit juice during the initial fermentation phase. It typically will damage the culture and/or cause mold to grow. If you would like to flavor your kombucha, you should do so during a second fermentation as described here.
Q: I just received the brewing kit and inside the culture bag there are two scobies. Should I just brew with one or use both?
A: Definitely use both—it means you'll have twice as much brewing strength for your first batch! Moving forward, with every batch you brew, a new culture will grow on top. You can keep brewing with numerous cultures, or just one, and use the new cultures to start additional brews, share with friends, etc. We recommend keeping no more than 3 cultures in your brew at a time. Simply toss out the oldest, darkest brown cultures as you go along.
To explain what's happening if you received two scobies, the darker brown one is the "older one" and the creamier one is the "newer one." At some point during their growing period at the brewery, the original culture had some kind of a disruption during its growing that caused it to grow, then drop to the bottom, and then it regrew an entirely new culture. It likely fused partly together, which is how they got packaged together.
Q: My scoby seems to be attracting fruit flies. How do I get rid of them?
A: Fruit flies can be a nuisance in the summer. Try making a fruit fly trap: take a small mason jar and fill it a third of the way with apple cider vinegar (or red wine vinegar, white vinegar, etc.). Drop a tiny dollop of soap in, cover with plastic wrap, and take a fork and poke a few small holes in the top. The idea is that the fruit flies go in but can't get back out. If you are having problems with bigger house flies, just make the holes slightly bigger for them. We promise this trap works like a charm!
Q: I accidentally moved my brew during days 2-7! Now my scoby is no longer on top of the jar. Is it still okay?
A: Not to worry! Kombucha is much less finicky than you'd think. Your original culture can sit on its side, float on the top, or on the bottom of the jar. So just leave it where it is and it'll brew up just fine. You'll see a new culture grow in across the top over the next week. Simply give it a few more days to brew than usual and perhaps wait to do you first taste test until day 10.
Q: I went on vacation and when I returned, my scoby had dried out in its jar. Basically all of the starter tea had evaporated. Do you think it's okay to try and use the scoby?
A: Unfortunately you won't be able to brew kombucha with this culture. The liquid starter is perhaps even more important than the scoby during the initial few days of brewing. Without it, the pH of your brew won't drop to the necessary level and you won't have enough yeast and bacteria to ferment the sweet tea.
Brewing kombucha is a learning experience! Next time just be sure to leave the culture with a few cups of starter tea to rest in so it doesn't drink it all up before you get home.
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 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 (in 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 you test the pH with culture in the jar?
A: To test the pH with the culture in the jar, you can slide the strip down along the side of the jar, or just lift/push the culture out of the way to dip test.
Q: My scoby has grown mold. Any thoughts on what went wrong?
A: Before you throw your batch out, make sure it's actually mold! Yeast bits can often times appear blue, green, or even pink, and look like mold. Check out our gallery of healthy/unhealthy cultures above. If you're still not certain, send us a picture at firstname.lastname@example.org and we can give you a second opinion.
The number one cause of mold is when the starter tea gets weakened. This means the sweet tea liquid was too hot before the scoby and starter tea were added to the batch in the beginning.
Another possibility is that the average brew temperature during fermentation is too cold. Brewing below 68 degrees can lead to mold as the yeast and bacteria grow so sleepy that they stop fermenting and airborne microbes are allowed to take over.
Other causes are using teas with oils in them. We recommend only using plain black/green/oolong/white teas. Always using at least some black tea as the base with a little bit of green tea for flavor (as opposed to doing just all green tea) will produce the healthiest culture and brew, as black tea is highest in important nutrients for the scoby.
Also, make sure to use only refined/granulated sugar when brewing.
Lastly, if your culture grew mold on it during storage, this means the top of the culture was exposed to too much oxygen and didn't have enough starter tea to rest in. Next time, leave at least 2-3 cups of liquid starter tea so that you can push the culture down into the liquid, leaving it more protected.
Other than those reasons, it's always possible that airborne molds can float over from kitchen produce, house plants, etc. and get in your brew jars. Try storing your brew jars in a more sterile area of the kitchen or house.
Q: I used green tea for my brew and it's barely producing a culture. Is that fine?
A: When using only green tea, it's very common for the culture to not grow as large. Your kombucha will still ferment all the same, the culture will just be thinner. The kombucha should still be done brewing after a few weeks, even if the culture isn't that large.
The reason this happens is that green tea has far less caffeine and fewer tannins, which are the two main nutrients in the tea that the culture feeds on. If you'd like to see your culture grow in a little thicker next time, I'd suggest using a combination of green and black tea. That way you can get the flavor of the green tea in your kombucha, but your culture will get the nutrients it needs from the black tea.
Q: Why can't I move my brew jar once I've started to brew it?
A: In the first 7 days of brewing, your culture is processing the tea and sugar and beginning to grow the new culture on top. Moving it disrupts this process and makes it hard to grow the new culture. Once the new culture has formed, you can gently move the jar, should you wish. Don't panic if you moved it around during the first 24 hours. Just try not to bump or move it during days 2-7.
Q: What is the purpsoe of the starter tea? Why can't I just add the culture?
A: Adding the starter tea immediately lowers the pH of the sweet tea from roughly 5.5 to 4.5 or below. This is the recommended pH to prevent the growth of harmful bacteria, molds, etc. and is why your brew can sit out at room temperature while brewing. It's particularly important in those first few days before your new culture grows on top, which acts as biofilm and protects the liquid below from airborne contaminants.
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, make one cup of hot caffeinated tea, and dissolve 1/3 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.