I love making kombucha and I often get asked about the process. While I actually wrote down quite a bit about the process over a year back (for my first blog project test) I never came around to actually post it.

Note: this is a c&p entry from an old test blog of mine. Formatting, content and pictures might be off.

The first fermentation (F1 for short) is the starting point of every brew. While the process in general is super easy, there are a few things that you have to consider. The chosen tee (main ingredient for kombucha brewing) has a big impact on the outcome. Not all tees are applicable for kombucha brewing! If this is your first try just use plain, unflavored black tee. Do not use Earl Grey, White Tee or any flavored tee, or you might end up with mold!

Preparations

For that you need a big vessel, preferable made out of glass. If possible, aim for a 4 liter (ca 1 galleon) vessel. Using smaller ones is possible, though it might not be worth the effort to go through the whole process for only one liter of kombucha, considering that you will re-use 1/5 of the fermented kombucha for the next batch. Also note that your fermentation times can drop drastically using smaller jars.

You also need something to cover the vessel, which keeps flies and dirt out, but allows the kombucha to breath. You can use any cotton fabric and a rubber band to fix it.

Vessels

For the fermentation vessel you will need a big glass (or maybe plastic) vessel that can hold up at least 3l of liquid. I personally go with a 5l vessel. You cannot use vessels where the liquid gets in contact with metal as the acidity of kombucha will interact with it. If you use a vessel with a spigot, ensure that it is stainless steel that can hold up against that acidity. Note that you do not need a spigot, it just makes bottling during f2 easier.

Scoby And Starter Liquid

To be able to start a batch of kombucha, you require a Scoby as well as some starter liquid (basically a part of a finished first fermentation) to kick-start the progress.

The Scoby is the main actor in the first fermentation. There are a lot of sources about what it actually is and how it does its thing, so I won’t go into detail about it here. Just know that it is a living thing and there are some basic ground rules to success, such as washing your hands before touching it and not exposing it to temperatures above 30 degrees Celsius.

The starter liquid ensures that the acidity of your first fermentation is high enough, so nothing bad can grow inside of it. This is why brewing kombucha is one of the easiest and safest fermented drinks you can make at home. As long as you stick to a valid F1 recipe and do not use flavored tee to start with the risk for mold is pretty much zero.

Sweet Tee

The sweet tee is the basic ingredient for brewing kombucha. In its basic form the sweet tee is nothing more than unflavored black tee and sugar. It has all nutrients that a Scoby needs. Other to adding the typical kombucha taste the Scoby will feed of the sweet tee, highly reducing the sugar content as well as increasing the acidity of the brew. I read that the sugar content is reduced about 90% within the first fermentation, though I cannot remember where so don’t quote me on that. However, I will do some tests regarding sugar content in the future.

The most important thing with your sweet tee is, that you use a fully fermented tee (black tee) without any added flavors or oils. The Scoby does not handle those well and mold can occur if you are not careful. Using other tees or ingredients is possible, though I would highly recommend you to try new ingredients in a smaller vessel as well as keeping a close look at the outcome.

As explained above the Scoby cannot stand temperatures above 30 degrees Celsius, so the temperature of your sweet tee must be below that threshold. To shorten the time, you can use only half of the water when making the sweet tee and adding the rest of the (cold) water afterward.

The Process

Sweet Tee

The first thing I usually do when starting a new batch is to make my sweet tee. Note that the following part depends on the chosen F1 recipe and the size of your vessel(s).

Example: For this example I will use my base recipe (3g of black tee and 50g of sugar per liter of water) and my 5.5 liter vessel, so I need 4l of sweet tee (and 1l of starter liquid) for one batch.

For the starter tee I use:

12g black tee 200g sugar beet sugar (or 240g cane sugar) 4l water First I heat up half of the water (2l). Once the water is boiling, I put it of the heat and add the tee. I usually put loose black tee in a tee filter and put a knot in it. You can also just use tee bags.

After letting it rest for 15 minutes, I remove the tee filter/bags, add the sugar and stir until it is fully dissolved. Then I add the other half of the water (2l). As discussed above the tee must cool down below 30 degrees Celsius before you can use it. If you have some cooler places nearby (cellar, outside, …) you can place the tee there. Just remember that the tee is sweet, so it may attract animals. Another approach would be to make the tee half a day earlier, so it is already cool when you start your new F1 batch.

Reserve Starter Liquid

If this is your first batch ever, you got a Scoby and some starter liquid from a source of trust, and you can skip this step.

If this is not your first batch you have to reserve some starter liquid for the next batch. Assuming that you will reuse the same vessel, put the Scoby and 1/5 of the finished F1 into another one for storage.

Bottling - Second Fermentation

Once you have put the starter liquid to the side, you can use the other 4/5 of the kombucha for second fermentation. Check out the Guide For Second Fermentation and my F2-Recipes.

Cleaning

Once the brewing vessel is empty, I usually clean it to remove Scoby rests on the glass and yeast from the bottom of the jar. While this step is optional (you can google for continues brewing) I just like to have my vessel cleaned. Also, the spigot will clock up after a few months without cleaning as a Scoby will start to form inside it. You can use a toothpick to remove it. Note that I usually do not use any products to clean my vessel. Warm water is enough, unless your batch went bad of course.

Starting The Next Bach

Once your jar is clean and the sweet tee is below 30 degrees you can start the new batch. Add your starter liquid (1/5) and the sweet tee (4/5) and mix them. Afterward add your Scoby. It does not matter how the Scoby lies in the vessel. Most of the time it will swim on top, but it can also happen that it swims on the ground or on the side of the jar.

Pro-tip: If your Scoby sinks to the bottom of the jar instantly, check if you put sugar in your sweet tee. Don’t ask how I found out.

After that, use a cotton fabric and a rubber band to seal your vessel. Put it in a dark space (or at least out of direct sunlight) with enough air ventilation, so it can breathe.

The Waiting Game

Now comes the hardest part for beginners: the waiting game. Depending on the temperature, this process can take between 7 to 10 days (potentially 4 days if you have a very small vessel and temperatures about 25 degrees). Try not to move it as you will rip up the Scoby one it tries to form. While this does not matter for your end product, the new Scoby will look pretty bad if you move it a lot. Again, this will not affect the quality of your kombucha, but it can gross new brewers out big times.

You can taste your kombucha at any time. At the beginning it will taste just like very sweet tee. After some days you will notice some acidity. The F1 is done once you have the balance between some rest sweetness and acidity. This highly depends on your preferences and is not exact science.

Once you decided your batch is done, you can start cooking up some new sweet tee and repeat the whole process.

The Fear Of Mold

Most people (me included) are most afraid of mold during the first batches. While I never had mold problems myself, I once tossed a batch because it tasted funny. I used way too less starter liquid (1/10) for that batch and I never had that problem when I used the right amount.

Following a few basic rules will keep your save:

If your F1 smells or tastes funny, toss it! There is no reason to drink it if you are not sure if something went wrong. Just start another batch. If there is fuzzy stuff on the top of your Scoby, its potentially mold. If there is non-fuzzy stuff on top, it is not mold (but probably yeast inclusions) If it is within the liquid (and you used 1/5 starter liquid as discussed above) it is most likely yeast and most certainly nothing bad. Don’t bother if your Scoby looks different from the ones you saw on pictures on some blogs. People usually only post pictures of pretty ones rather than ugly ones.

Yeast

This threw me off during my first batch. It looks gross but is totally normal, gets more if the temperature rises about 25 degrees though adds a lot to the taste of your brew.