Kombucha: Why It Is Good for You, and How to Make Your Own

What is kombucha?

It is very likely that you’ve heard of the name “kombucha” before, but do you actually know what it is? If not, this post will shed some light as to where it comes from, what are its benefits and how to brew your own kombucha.

Kombucha is a fermented, lightly effervescent, sweetened tea drink. Its popularity might have grown thanks to a marketing and wellness hype, but it has been around for more than 2,000 years. It was first brewed in China and then spread to Japan and Russia. It became popular in Europe in the early 20th century and sales in the United States have been on the rise since the early 2000s.

What is kombucha made of?

The basic ingredients in kombucha are bacteria (the good kind), yeast, sugar, and black tea. You can also make it with green, white or oolong tea, but not with any tea containing oils (e.g. Earl Grey) because it will harm the bacterial host. The mix is set aside for a week or more, enough time to allow bacteria and acids to form in the drink, as well as a small amount of alcohol (usually less than 0.5%). This process is known as fermentation. Kombucha bacteria includes lactic-acid bacteria, which can work as a probiotic, as well as a healthy dose of B vitamins.

What does kombucha do for your body?

Advocates say it helps your digestion, frees your body of toxins, and boosts your energy. It’s also said to boost your immune system, help you lose weight, ward off high blood pressure and heart disease, and prevent cancer. But there’s not a lot of evidence to support these claims.

Evidence-based health benefits of kombucha

Although research is limited, there’s evidence the fermented tea offers some health benefits:

It contains probiotics. Those live microorganisms are found naturally in fermented foods like kimchi, kefir and kombucha. They help with diarrhoea and irritable bowel syndrome (IBS), and they may even strengthen your immune system.
Fermented products in general are good for your gut microbiome. “Good” bacteria are essential for it to thrive.
Kombucha also contains antioxidants which are substances like vitamin C, selenium, and carotenoids, that can help to prevent or delay cell damage. This can help limit chronic inflammation that can lead to health issues such as heart disease, cancer and arthritis.
Used as an alternative to soda drinks (which contain no nutritional benefits) or alcohol (which can be high in calories), kombucha can be a positive step within a weight-loss plan. Kombucha contains a bit of caffeine too, and research has shown that caffeine can promote weight and body fat reduction.

If you enjoy it, kombucha can certainly be part of your overall gut-health-supporting strategy. But bear in mind it should be enjoyed in moderation: a glass of kombucha every day is fine, but try to limit it to less than 450ml a day. Kombucha is best consumed on an empty stomach, or 45–60 minutes before or after meals.

Kombucha risks

Kombucha is not recommended to young children, or anyone who should avoid foods containing raw forms of bacteria, including pregnant women or those breastfeeding. And if you have a weakened immune system or have had a severe infection or surgery in your intestines, there is a higher risk that bacteria may pass through your gut and cause a blood or whole-body infection. For that reason, probiotic foods like kombucha aren’t recommended if you have “leaky gut,” colitis or coeliac disease.

While kombucha does contain antioxidants and probiotics, there are also a few risks associated with the beverage – but these are mostly associated with incorrectly brewing kombucha at home. Making kombucha involves letting bacteria grow in a liquid you’re going to drink, and if it’s not prepared properly, it can grow harmful bacteria or even mould.

How to make kombucha at home?

This fizzy probiotic fermented tea has quickly gone from niche to mainstream, showing up in grocery stores as well as restaurants and trendy bars. But it’s usually quite pricey… Thankfully, the much cheaper alternative of making your own kombucha is easy and only takes a few minutes of hands-on time! Let me show you how with the step-by-step guide below.

How to make a SCOBY from scratch

First things first, you will need what is called a “SCOBY”, acronym for “Symbiotic Colony Of Bacteria and Yeast”. Like its name suggests, it is formed by the bacteria and acids fermented by the sweetened tea. The SCOBY is sometimes referred to as the “mother,” “starter” or “mushroom,” since it is the source of the live bacteria that infuse the tangy flavour and probiotics into the mix. It’s the thick, slippery mass made of cellulose that forms across the top of raw kombucha.

You have 3 possibilities: either you buy a SCOBY online, either you know someone who is brewing their own kombucha and is able to give you one, or you can make your own from scratch. In case you choose the latter, below will be what you need:

1 big glass jar (ideally 4L)
7 cups (approx. 1.5L) of clean filtered water
1/2 cup (approx. 125mg) of cane sugar
4 bags of black tea (or 1 tbsp of loose tea)
1 cup (approx. 250ml) of unflavoured kombucha (bought in store)

Bring the water to the boil and remove from the heat. Add the tea, then stir in the sugar. Leave it to cool down to room temperature, and only then, add the unflavoured kombucha (so you don’t kill any live bacteria). Cover the jar with a clean tea towel to let it breathe and secure it with an elastic band before storing it in the dark, or at least away from direct sunlight.

It takes roughly 2 to 4 weeks to grow a new SCOBY from scratch. The time might be less if your kitchen is warm (above 20°C) or longer if your kitchen is cool. Be patient and leave it to do its thing, but keep an eye on it regularly.

First fermentation of homemade kombucha

You now have your own SCOBY? The process for the first fermentation is very similar, just double the quantity so you can prepare more bottles in one go. And instead of a store-bought kombucha for the starter, you can use your own. You will need:

1 big glass jar (ideally 4L)
14 cups (approx. 3L) of clean filtered water
1 cup (approx. 250mg) of cane sugar
8 bags of black tea (or 2 tbsp of loose tea)
2 cups (approx. 500ml) of the starter tea you created when you made your first SCOBY – if you bought it online, the starter tea will be included with your purchased SCOBY
1 SCOBY

Step 1: Prepare the sweetened tea with the quantities listed, and let it cool down (you can speed up this step by placing a big bowl full of ice cubes underneath).

Step 2: Make sure the tea is below 32°C – it’s important that the tea is cool enough to avoid damaging the live culture. Then you can add your SCOBY and your starter tea.

Step 3: Secure the jar with a clean tea towel and an elastic band to keep insects away. No lid, your kombucha needs to breath – it’s alive!

How to know when your kombucha is ready to bottle

It usually takes at least a week (around 7-12 days), but it can vary depending on the temperature of the room (quicker if warmer).

Below are the pictures of what you can expect to see. In my case, a new layer of SCOBY has appeared the next day and has thickened quickly over the week. The mother SCOBY underneath has come back up to the surface too. Sometimes it can stay at the bottom of the jar or float around, it’s okay either way. At this stage, you have unflavoured and un-carbonated kombucha.

After a week, you can already taste it. The acidic (but slightly sweet) flavour will tell you that your brew is ready. The taste should be similar to apple cider vinegar, although it smells nicer (in my opinion): a little bit sweet with a vinegary flavour. The longer you leave your kombucha to brew, the stronger the vinegar taste will be. The pH should be in the range of 2.5 – 3.5.

Make kombucha fizzy with secondary fermentation

This step is not mandatory, some people like to drink kombucha right after the first fermentation (unflavoured and un-carbonated), and that’s totally fine. Second fermentation is the process through which you flavour your brew and put it into a sealed bottle, which traps carbonation into the liquid. It typically takes 2-10 days, but can take longer.

By letting yeasts eat up the sugar and convert it into carbon dioxide, the drink becomes fizzy. Most of the time, the sugar added during the first fermentation will be eaten up and what’s left is not enough to carbonate the drink. It means you need to add more sugar, usually coming from fruit. Steps are once again easy to follow:

Choose glass bottles with an air-tight seal cap
Remove the SCOBY and reserve 2 cups of kombucha for your next batch (starter tea)
Stir the remaining kombucha in the jar to redistribute the yeast and bacteria – it will make the carbonation more consistent across all bottles
Pour the kombucha into the bottles but make sure you leave at least 3-4 cm of head-space at the top
Time to add your flavour(s)! There is no set-in-stone rule here. Feel free to test and see what you prefer: more quantity if you want a stronger fruit flavour, fresh fruit, fruit juice or fruit puree… It’s all down to personal preference. You can experiment safely as this part will not throw off your fermentation process.
Seal them tightly and keep them in a dark cupboard.
Make sure you “burp” the bottles every day to allow excess air to leave (open and close the lid quickly) – it will help prevent explosive results!

After a few days at room temperature, store them in the fridge (for up to 2 weeks) to help keep the carbon dioxide in the liquid, so it’s less likely to fizz over and make a mess when you open it. The exact time it takes to carbonate really depends on the flavours, some will get perfectly fizzy in 3 days, others will need a full week before they get to similar carbonation level.

Do I need a SCOBY hotel?

If you have read it this far, you’re probably wondering what to do with this extra SCOBY that you will create with each batch of kombucha? That’s right, if you keep brewing, you will find yourself with many SCOBYs in no time at all. Each one of them can be reused several times, so it would be a shame to throw them away after a single use. You can either give some away to your friends so they can brew their own kombucha too, or you could keep a “SCOBY hotel”.

Basically, you keep a glass jar with your SCOBY and at least 2 cups (approx. 500ml) of kombucha. Then each time you make a new brew, you add the new SCOBY with some fresh new kombucha, right after the first fermentation stage. This is a very effective way to create a super-charged starter tea that you can use for all future batches. It will taste like vinegar and smell really acidic, which is perfect for a bacteria-rich starter tea.

Tips when making kombucha

It’s normal to be a bit wary at first. Read the tips below so you don’t make any beginners’ mistakes when brewing your first batch of kombucha:

Use glass, stainless steel, or plastic containers (not ceramic or clay containers)
Keep everything sanitary, including the equipment and your hands
Don't let your tea infuse for too long, or the taste can become overwhelming
Ensure your freshly made tea is cooled down before adding your SCOBY so you don't accidentally kill it
Sugar is a crucial ingredient and cannot be replaced by sweeteners, just leave it to ferment for longer if you want it sugar-free
Stir your kombucha before bottling, for consistent carbonation
Only add flavours during the second fermentation, as flavouring can negatively impact your SCOBY
Keep temperature consistent during fermentation, only refrigerate when it's ready to drink
Re-use your SCOBY several times before tossing it