While it has existed for centuries, kombucha has become a recent growing trend thanks to its wide range of potential benefits to health and wellbeing. Made by fermenting tea, kombucha is known to contain probiotics that can help your gut flora, including Gluconacetobacter, Lactobacillus, and Acetobacter, as well as beneficial yeast populations dominated by Zygosaccharomyces.1 Learn how you can make a batch of healthy, probiotic-rich kombucha below.
A Strong, Healthy SCOBY
All good kombucha starts with the SCOBY, which stands for “symbiotic culture of bacteria and yeast”, and is also known as the mother or starter. The SCOBY is a complex community of bacteria and yeast that is responsible for fermenting the tea and turning it into kombucha. Visually, the SCOBY looks like a gelatinous blob, but it is literally the living component of kombucha and provides the beverage with its characteristic active cultures. A SCOBY that is not healthy may spoil your brew or prevent proper fermentation. A healthy SCOBY looks thick and rubbery. Lumps, bubbles, and dark spots are normal and nothing to worry about. If your SCOBY has mold, fruit flies, or vinegar eels (a type of nematode), it’s time to throw it away. As long as it has a steady supply of tea and sugar to feed on, a SCOBY can last for years, growing and creating SCOBY babies, daughters, or “SCOBlets.”2 You can buy SCOBY kits, get SCOBYs from a friend, or grow your own from raw, unflavored kombucha.3
What Makes a Good Kombucha?
Kombucha only requires four ingredients: water, sugar, tea, and the starter SCOBY. With such a simple list, the key to a good kombucha comes down to choosing clean, minimal, high-quality ingredients.
Black teas are ideal for kombucha as SCOBYs prefer tea that is high in tannins, which are the organic substances in tea that provide its slightly bitter flavor. Green tea, white tea, and even lower-caffeine teas may have trouble activating starters on their own, but they can be mixed with black tea to ensure proper fermentation. You should also avoid any teas that contain added flavors, which can also interfere with fermentation. While you can absolutely use teabags to make kombucha, organic loose-leaf teas offer a higher quality brew that is worth the extra effort.4
The water used for kombucha should be as clean and free of contaminants and additives as possible. Unlike other fermented drinks, high mineral content is not ideal for kombucha and may actually hurt the SCOBY. Stick with distilled water or filtered spring water. If tap water is your only option, make sure you boil and filter it to remove the chlorine, fluoride, and other chemicals.5
While it might seem like a good idea to use a high-quality sweetener, like raw honey or organic maple syrup, plain granulated sugar is the best option for kombucha. It is free of extra minerals and is the most easily digested sugar by the yeast and bacteria in the starter.4
Step-by-Step Guide to Kombucha
For equipment, you will need:
- A 1-quart jar
- A wooden stirring utensil
- A cheesecloth or tight-weave cloth
The ingredients you will need for a 1-quart batch of kombucha:
- 2 tea bags or 7 grams of loose-leaf tea
- 70 grams of sugar
- Half cup of vinegar or starter tea (tea from a previous batch of kombucha)
- 1 quart of water
- Bring the water to a boil in a pot over high heat. Add your sugar, stirring to combine and dissolve. Add your tea, allowing it to steep for 15 minutes.
- Let the tea cool to room temperature. You can steep the tea for longer than the 15 minutes if you want it stronger. Otherwise, remove the tea bags or strain the liquid through a mesh strainer covered with the cheesecloth or coffee filter into a separate pot. It is important to cool your tea before adding it to the SCOBY or starter tea. High temperatures will kill the active bacteria and yeast.6
- Once the tea has cooled, add the starter tea or vinegar.
- Pour the mixture into your 1-quart jar, and add your active SCOBY.
- Cover your jar with a clean cheese cloth secured with a rubber band. Your SCOBY needs to breathe for proper fermentation. The cheese cloth allows for plenty of oxygen while keeping out pests, dust, and other potential contaminants.
- Allow your kombucha to ferment at about room temperature (from 68 to 85°F) in a dry area, outside of direct sunlight. Depending on your personal taste and your SCOBY, you can leave your kombucha to ferment anywhere from a few days to a whole month. Keep in mind that the longer you let your tea ferment, the more sugar that the SCOBY eats, creating a less sweet, more tangy and vinegar-y flavor. You can taste every day or two to determine the progress of the fermentation.
From there, your kombucha is ready to enjoy plain. Pour off the top to consume, and bottle it to stop the fermentation process. If you want to keep your SCOBY active and alive for future batches, retain enough liquid at the bottom to keep the mother submerged.7
However, you can also flavor your kombucha with fruit juices and allow for a second fermentation. To do this:
- Stop the initial fermentation at 5 to 10 days. The kombucha should still taste slightly sweet and slightly tart. You still want some sugar for the second fermentation, on top of the sugar from any fruit juice you add.
- Transfer some of your kombucha from the jar into a sanitized, fermentation-grade bottle. Add juice. Make sure to leave at least a few inches of head space at the top of the bottle, which provides room for pressure from air and carbonation.
- Let these bottles sit for 5 to 14 days at room temperature. Opening the bottles will end the second fermentation, so be patient and allow the kombucha to go at its own pace.
- Chill the bottles before opening to reduce some of the pressure, and keep refrigerated for maximum enjoyment.8
Preventing Mold Growing in Your Kombucha
A moldy or dead SCOBY spells doom for your kombucha and ill health for you. Here are some tips to prevent mold from growing on your SCOBY.
Use Sanitary Equipment
From your jar to your utensils to your brewing pot, make sure everything you use in the brewing process is clean. Wash everything with soap and warm water, making sure to rinse thoroughly. For added peace of mind, you can also rinse your equipment in distilled vinegar and filtered water.9
Keep a Clean Workspace
Along with your equipment, make sure your work area and storage space are clean. Indoor plants may contain some trace mold spores in their potting soil, so keep them away from where you store your kombucha. Avoid placing your kombucha near an open window, and do not smoke around your kombucha.9
Wear Gloves and Avoid Touching Your SCOBY
The germs and natural oils on your hands can potentially contaminate the SCOBY, which can result in mold.9
Maintain a Low pH
A low pH means a more acidic environment that is not welcoming to mold. Adding enough starter tea or vinegar in the initial brewing process should keep mold away. 9
Use High-Quality Ingredients
Along with adding to the general taste and health benefits of kombucha, using high-quality ingredients should maintain a healthy SCOBY. Old tea leaves may be dusty or moldy, while unfiltered water can contaminate with other chemicals. 9
Alcohol and Caffeine Content
Some kombucha fans are worried that the beverage will cause them to get a little tipsy. It’s true that kombucha contains a small amount of alcohol. Alcohol is a natural product of the fermentation process. As the yeasts consume the sugar, they release carbon dioxide (which provides kombucha’s characteristic carbonation) and some alcohol in the form of ethanol, but before you worry about getting a buzz from kombucha, understand that the process is highly self-limiting.10 As the yeast produces alcohol, the bacteria consumes the alcohol and turns it into acid. It’s a steady, self-regulating cycle.11 Most kombucha contain less than 0.5 percent ABV, which is less than a loaf of bread, which can potentially contain residual alcohol levels up to 1.9 percent. Compare that to 5 percent ABV in a light beer.10
Considering kombucha is made from tea, it also invariably has some caffeine in it. The fermentation process does, however, cut down the final caffeine amount. A bottle of kombucha still contains less than a quarter the amount of caffeine than an 8 oz. cup of coffee. This makes it good for those trying to wean themselves off of caffeine, but bad for those who are looking to caffeine to get their days started.10
Kombucha Shelf Life
When well taken care of, a SCOBY will last you years. Kombucha itself has a technically indefinite shelf life.12 As long as you store it in a sealed bottle, kombucha is good for about three months in the fridge. Even after that period, it may taste a little old and similar to vinegar, but it is still safe to drink.13 However, there’s no guarantee it will have the same texture or alcohol content six months after it was original brewed. Depending on the active fermentation, the alcohol content could increase if the kombucha is not refrigerated or stored properly. Granted, if you are a kombucha fan, it likely will not last that long in the first place.