What is kombucha?
Kombucha may seem like a ‘new’ summertime drink, but its earliest records date back to over 2000 years ago! Having originated in northeast China, the popularity of this beverage spread rapidly with documentation in Russia and Korea in the year 414.
Kombucha is a refreshing, slightly sweet, and slightly carbonated beverage made from sweetened tea that's been fermented with the help of a bacteria and yeast culture called a 'SCOBY". SCOBY stands for symbiotic culture of bacteria and yeast. We get a lot of questions about SCOBY, which are discussed in the common questions and answers section below. Let's take it one step at a time. The fermentation that SCOBY promotes is essentially the chemical breakdown of compounds into simpler substances with the help of microorganisms such as bacteria and yeast. Some examples of fermented food and beverages other than kombucha include beer, wine, bread, yogurt, kimchi, and sauerkraut.
We find that kombucha tastes like a cross between an alcoholic cider and a sugary tea, because that's basically what it is. Through the process of fermentation, the bacteria and yeast in the SCOBY consume most of the sugar in the tea. As a result of the SCOBY feeding on the sugar, they release a very small amount of alcohol (often less than 1 or 2%), plus carbon dioxide into the drink. If the drink ferments for longer than a week, it develops a rather vinegary taste which some prefer, while others dislike.
On the first try, some people love kombucha, while for others it's an acquired taste. It can be like trying a beer, wine, or coffee for the first time. It takes some getting used to. The flavour of kombucha can also taste vastly different depending on the type of tea used (black, green, oolong, etc.), the length of fermentation (3 days versus 14 days), and the flavourings added (unflavoured versus fruit flavoured).
Kombucha's health benefits
This popular fermented beverage has been noted for its potential health benefits, including:
No. 01 | Antioxidants, vitamins & minerals. The benefits of drinking tea have been widely noted. Since kombucha is prepared from tea, it contains polyphenols (antioxidants), flavonols (antioxidants), amino acids (protein building blocks), vitamins (including E, K, A), low levels of B vitamins, vitamin C (if prepared using green tea), and minerals (including iron, manganese, zinc). |
No. 02 |
Probiotics. Probiotics are live microorganisms that help with health promotion. Kombucha is prepared using a culture of bacteria and yeast (which are live microorganisms), so it provides beneficial probiotics, which in turn help support gut health. |
No. 03 | Aids in digestion & immune function. Probiotics play a role in establishing and maintaining optimum immune health. This may be why kombucha has been highly regarded for protecting us from infections and disease. |
No. 04 | Alternative to sugar-sweetened beverages. Given that kombucha can be flavoured in countless ways and is carbonated, it's a satisfying substitute for sodas that contain high levels of added sugars. It can also be enjoyed as a replacement for alcoholic beverages for those looking to reduce this intake. Although sugar is still added to kombucha to feed the yeast, a large portion of it is consumed and converted to carbon dioxide, which contributes to the fizziness of the drink. |
The potential risks of kombucha
Although the benefits are many, it's important to also note the two main potential risks when preparing kombucha at home:
No. 01 |
Pathogens. Under non-sterilized conditions at home, there's a possibility of contamination by potentially pathogenic (disease-causing) bacteria and yeasts. Although contamination is a risk, the kombucha brew is said to protect itself against foreign microorganisms in two ways: 1) Competition between the many microorganisms in the SCOBY versus the few the invaders. Picture trying to squish onto a bench that's already full of people. With more people, there's less space for us to settle down and find a comfortable seat. In a similar way, with lots of beneficial microorganisms in the SCOBY, there's less space for invading disease-causing bacteria to join the party. 2) The low pH, or acidity, of the brew from what's called acetic acid helps prevent the growth of many bacteria. |
No. 02 | Contamination. If incorrect equipment is used, toxic elements such as lead can leach into the beverage during preparation. This is why it's important to brew kombucha in a glass container and to ensure the brew does not come into contact with metals. |
General Insights & Tips
Best practices
We recommend the following when making a brew at home:
- Clean hands thoroughly with soap and rinse well. Avoid wiping your hands on a dirty cloth or pants after washing them.
- Clean containers and jars. Ensure all containers are clean and free from soap suds to avoid destroying the SCOBY. If possible, rinse the inside of containers and jars with a little bit of apple cider vinegar to mildly sterilize it. We recommend using glass containers over plastic or metal ones, which may leach undesirable chemicals or metals into the drink as discussed below.
- Avoid metal as it can leach into the brew, affect the kombucha’s taste, and damage the SCOBY’s growth. It's also not good for our health to consume leached metals. It’s okay to use metal utensils when preparing the tea, but avoid metal once the SCOBY has come in contact with the brew. If using a large glass container with a spigot, choose a container with either a plastic spigot or a high-quality stainless steel spigot (304 grade or higher) to avoid leaching metals.
- Choose the right fermentation location. Place the container in a cool and dark place. An ideal location is away from direct sunlight and a place where the temperature is steady. Tucking the container away in the corner of a room or in a cupboard is a great option.
- Choose the right teas. Suitable teas include green tea, black tea, white tea, oolong tea, or a mix of these. Avoid using flavoured teas, herbal teas, or teas that contain oils such as Earl Grey.
- Ensure the correct ratio of ingredients to batch size. When making more or less kombucha, keep in mind the ratio of ingredients to each other matters. Stick to the ratio of, 1 cup of sugar : 8 bags of tea : 2 cups starter tea : 14 cups (approx. 3½ litres) of water. Divide or multiply by these numbers accordingly to get the volume you desire. Regardless of volume, one SCOBY is all you need, just keep in mind that a larger batch will take longer to ferment.
- Allow the sweetened tea to fully cool before adding the SCOBY to it, otherwise, there's a risk of killing the microbes from the heat.
Fermentation duration
Fermentation duration varies based on the environment's temperature and the size of the SCOBY. When the weather is cooler, the brew needs longer to ferment. This is because the bacteria and yeast are less active in the cold. On the other hand, in warmer weather, the bacteria and yeast are more active meaning the brew needs less time to ferment.
The amount of bacteria and yeast also affects the fermentation duration. With each new batch of kombucha made, a new "baby" SCOBY grows from the original "mother" SCOBY. This is normal and actually desired! With each new batch of kombucha made, if the SCOBY layers stay in the container, there's a larger amount of bacteria and yeast to eat away at the sugar than before. Overall, fermentation duration shortens with more SCOBY layers because there's more bacteria and yeast present. To slow down the fermentation time, simply remove one or more SCOBY layers from the container. If you prefer a sweeter tasting brew, brew for less time compared to brewing for longer durations for a less sweet brew.
Secondary fermentation
Secondary fermentation is optional but necessary for carbonation. This means for a fizzy kombucha drink, secondary fermentation is needed.
After about 6 days have passed with the SCOBY in the sweet tea, taste-test the drink. If you enjoy the taste, drain and bottle it in glass bottles without a metal lid. To help the yeast make carbonation, add cut-up fruit and/or fruit juice to provide sugar and add flavour.
We usually aim for a ratio of 80% kombucha to 20% fruit juice.
An alternative to fresh fruit is using 1 tsp of sugar per litre of bottled liquid, but we find fresh is best. The microbes will then feed on these sugars, leaving little of it for us. As a result, they release gas which gives fizz to the drink.
Leave about 1 inch (2 cm) of air at the top of the bottles. Secure the lid and store the bottled kombucha at room temperature out of direct sunlight for 24 - 48 hours to promote carbonation. After this, refrigerate the bottles to stop the fermentation and carbonation.
Flavouring kombucha
One of the many pleasures of making kombucha at home is the endless flavour combinations to experiment with. This flavouring can occur in the second fermentation step of making kombucha and is optional, as outlined above.
Flavouring with herbs (and even spices like cardamom or cinnamon) can bring a really unique flavour profile to the drink. Have fun and get experimenting! Fresh herbs like basil, thyme, mint, and rosemary work especially well.
Keep in mind that the fermented kombucha is naturally already acidic. In order for the drink to yield maximum flavour and carbonation, it's best to provide the SCOBY with fruits that are on the sweeter side, and less acidic.
It's alright to add lemon or lime (which are acidic) if desired, but try to balance this out with sweeter fruit, like mango, peaches, or berries. Note that these fruits can be cut-up, pureed, or added in juice form. Personally, we prefer juice because cut-up fruits get broken down by the acid in the kombucha and tend to get quite mushy.
The list of flavour combinations is never-ending. The following are just a few ideas to start experimenting with.
- Apple + ginger
- Blueberry + ginger
- Persimmon + ginger
- Lemon + ginger
- Mango + peach
- Mango + strawberry
- Mango + passionfruit
- Pomegranate + passionfruit
- Pomegranate + pineapple
- Apple, cinnamon + cardamom
- Pineapple + coconut water
- Lemon, peach + blueberry
- Strawberries + basil
- Blackberries + thyme
- Blueberries + rosemary
- Raspberries, lemon + ginger
- Mixed berries + mint
- Watermelon + lime
Common questions and answers
SCOBY won’t float?
The location of the SCOBY in the jar doesn't actually matter. Sometimes it sinks, sometimes it floats, and sometimes it's laying sideways in the jar. Not to worry! Within a few days, a new, often cloudy looking, cream-coloured layer of SCOBY should start forming on the surface of the kombucha. This is called the "baby" SCOBY. If the "mother" SCOBY (the original SCOBY) floats to the top, the new baby SCOBY will attach to it. If the mother SCOBY never makes it to the top of the vessel, the new "baby" SCOBY will form separately from the "mother", and that’s okay too. Just make sure the new SCOBY looks healthy. It should be free from visibly black and mouldy spots.
Smells like vinegar?
In the beginning, the kombucha will have a neutral or even sweet smell. As the fermentation progresses, the brew will begin to smell more like vinegar. Don't worry, this is normal. If you prefer a brew that tastes on the sweeter side, ferment it for a shorter duration of time. Taste test the drink as early as 3 days into fermentation and bottle it when it's at the desired sweetness level. For less sweetness, allow the drink to ferment for longer. The bacteria and yeast will continue to eat up the sugar over time making the final product less sweet.
Does the size of my first SCOBY matter?
Not at all! If the original mother SCOBY is small compared to the size of the vessel, then it might just take longer to ferment. The new baby SCOBY will grow to fill the size of the new container over time. Cool stuff right?
Strings floating in solution?
We'll sometimes see brown strings floating in the solution or attached to the SCOBY. These are normal strings of yeast. Don't cut away or discard these strings, as they're a healthy and normal part of fermentation. Although they're harmless, with time some of the particles from the strings may settle near the bottom of the container and clog the spigot. When this happens, cleaning the container may be necessary.
Coloured patches on the SCOBY?
Small holes, bumps, different shades of cream, light brown, and/or clear jelly-like patches are completely normal. The differences in colour that make up the SCOBY are usually from changes in the environment where the container has been placed.
Dark black spots, however, may indicate the growth of ‘bad’ bacteria or yeast. If mould is visibly present, something has gone wrong. When in doubt, throw it out and start over. This includes discarding both the tea and the SCOBY.
Fruit flies on the SCOBY?
Seeing fruit flies in the container is a sign to throw everything out. It may not be visible yet, but those fruit flies have laid their eggs. The SCOBY has been contaminated and starting over is necessary. We learned this the hard way and that's why we personally advise against using cheesecloths as a cover. Cheesecloth holes tend to be large enough for little fruit flies to crawl into and wreak havoc.
Kombucha isn't that fizzy?
This might be for a few reasons. Here are some things to consider: 1) Leave enough room at the top of the bottles; at least 1 inch (2cm) of space, 2) add sweet fruit juices so that the microbes have some sugar to eat; it's this sugar that gets turned into carbonation, 3) choose bottles which have lids that secure tightly; this is so that no gas escapes, and 4) ensure sufficient second-fermentation time outside of the fridge; about 24 - 48 hours in total should suffice.
Going on vacation?
If the vacation is longer than 3 weeks, place the SCOBY and starter tea, combined with a fresh batch of tea, in a sealed glass container in the fridge. This mixture will last for about 6 weeks.
If going away for 3 weeks or less, simply make a new batch before departing. When returning home, discard most of the kombucha, but reserve 2 cups as a starter, and start a new batch. There should be nothing wrong with the kombucha made while away for less than 3 weeks. It may just taste too much like vinegar to enjoy drinking it.
SCOBY layers getting thick?
Every once in a while, separating your SCOBYs and either starting a “SCOBY hotel”, or giving some away to friends or family will be needed. It’s also always a good idea to have at least an extra few SCOBYs in the fridge just in case something contaminates the existing brew or starting over is needed.
To remove some layers, peel off the bottom (oldest) layer every 2 - 4 batches. We try to limit the kombucha to no more than three SCOBY layers at any one time. This is because we find the brew ferments too quickly and we aren't usually able to drink enough kombucha to keep up when there are more than 3 SCOBY layers. By removing a SCOBY or two, the fermentation time slows down.
Need to clean the container?
Before starting a new batch, remove the SCOBY and starter tea and place them in a clean glass container. Wash out the large vessel by rinsing with hot water and then rinsing with apple cider vinegar. Allow the water or vinegar to run out through the spigot as well to clear out any strings that might be impeding the flow of liquid.
Summary
- Kombucha is a fermented beverage. It can be made at home using a large glass container, tea bags, some hot water, fresh fruit/juice, sugar, a paper towel, and SCOBY.
- Avoid metal, flavoured teas, cheesecloths, and dirty hands or equipment. Using these may lead to toxic chemicals or bacteria contaminating the brew.
- There are two fermentation steps. The first fermentation impacts the taste whereas the second helps add flavour and fizziness to the drink.
- When in doubt, throw it out. Signs that homemade kombucha has gone bad include visibly black and mouldy spots or odours.
- The possibilities are endless. Be sure to share your creations with us on Instagram with the hashtag #pickuplimes
Discussion & Rating
I bought a bottle of Synergy raw kombucha. I read it was good as a probiotic. But now it has been sitting in my refrigerator for over a month, and I am afraid to drink it. LOL
I have been reading about the possible leaching of lead, and I certainly don't need that!
Also, if I drink it on an empty stomach could I possibly experience some nausea?
Thank you, and I really enjoy your website/YouTube/Instagram.
This article helped me to understand what kombucha is 🙏
Now I am curios to know why using flavoured teas, herbal teas, or teas that contain oils such as Earl Grey is not suitable for kombucha 🤔
It's funny, but I got my baby scoby exactly the same day when the video with Sadia getting it was released :)))
So the info is extremely helpful! Enjoying my homemade mint kombucha 😊🌺🥤❤️
Hi Sadia, would you consider making a video on homemade kombucha? Sharing the recommended vessels, how the troubleshooting looks like, how to start from scratch and maintaining SCOBY, and all the good stuff you have in the PDF? It's a lot easier to hear from you talk about it :D
I'm making my first Kombucha batch and this is extremely helpful! Thanks PUL team ☺️