Kombucha almost needs no introduction.
Consumed by Monks, Grannies, and Hipsters with equal gusto; it’s an easy to make go-to probiotic drink.
Essentially kombucha is fermented tea – the magic comes when you add the different flavourings and botanics. The first time I drank kombucha was in Guatemala, and I was intrigued with the acidic, vinegary but pleasant effervescent taste. I had never had anything like it before.
Kombucha is fermented using a SCOBY, which stands for “Symbiotic Colony Of Bacteria and Yeast”. Essentially it’s a collection of yeasts, fungus, and bacteria clustered together to form a placenta-like looking mushroom. But don’t let that put you off! The technical name for this mushroom is a “zoogleal mat”, or more colloquially “The Mother”. Let’s refer to the Kombucha SCOBY as “The Mother.”
Legend has it that the first recorded use of kombucha comes from China in 221 BC during the Tsin Dynasty, where it was known as “The Tea of Immortality”.
It’s known in Chinese as chájūn, Japanese as kōcha-kinoko, Korean as hongchabeoseotcha, Vietnamese as tra nam and Russian as chaynyy grib and these names translate literally to “tea fungus” or “tea mushroom.”
I am an absolute tea-connoisseur, so I love kombucha, as you get to play with lots of different types of teas. If you have a favourite tea that I haven’t included in the recipes, go ahead and use it.
These are the variables in kombucha fermentation, which will affect how long it takes to ferment:
- the temperature
- the tannins in the tea
- the quantity of sugars
- the strength of your mother
- and the ratio of The Mother: liquid.
Use your intuition, the guidelines below and taste preferences to guide you. It should taste acidic and a little vinegary when you bottle it.
If it’s still too sweet, it needs to ferment longer.
Prep Time: 15 mins
Fermenting Time: 7 days – 8 weeks
Shelf Life: around 12 weeks refrigerated
Yield: 1 litre
1 x 1.5 litre open mouth glass jar
1 litre glass bottle with tight fitting lids
Funnel to decant the brew
Sieve (plastic or metal)
1 x elastic band
1 x piece of muslin cloth or clean chux cloth
Type of Bottle:
I recommend using a sturdy, narrow neck bottle (similar shape to a Champagne bottle), as this shape will encourage carbonation to develop. The lid needs a good seal so that the fizz stays in the bottle. You can use the grolsh style flip-top bottle.
Kombucha House Keeping:
- The Mother may sink to the bottom of your fermentation vessel – this is ok for the first three days or so of your fermentation. If after three days it hasn’t risen to the surface of the brew, it may not be viable and you should source a new Mother.
- If using flavoured teas, like Earl Grey or herbal tea, rotate the Mother to plain black tea after harvesting your kombucha, as the oils and herbs may affect it.
- A thin transparent film may appear on top of your brew or The Mother – this is the new baby SCOBY. As your Mother grows, either peel off the layers, using clean hands, and re-use them, or just leave them all intact. The fatter your Mother, the quicker the ferment will be, so keep this in mind.
- Use food grade BPA plastic or glass vessel for fermenting – stainless steel can impede the fermentation
- The Mother will take the shape of the fermentation vessel it’s placed in – I’d love to see a heart-shaped one!
- If you want to avoid caffeine, use weak tea or decaf tea. If your Mother starts to look a little less vigorous, give her a rest in a strong sugar/caffeinated tea mixture for a couple of rounds to get her back to life, then repeat with the decaf procedure.
Kombucha fermentation troubleshooting:
The Mother you need to ferment a 1 litre brew is around the size of your palm. When it gets bigger than that, you can double the quantity of tea and honey.
A bigger Mother will ferment much quicker and could turn vinegary much quicker.
A smaller Mother will take a longer to transform the sugar tea.
It’s not an exact art, and you will figure out what works best for you, so use this as a guideline.
Occasionally, you may notice mould growing on The Mother. This could range from white to black and furry. I recommend discarding this Mother and the kombucha and sourcing a new Mother.
It’s not worth risking your health for mould.
Strands and floaty bits hanging off The Mother is normal and you can drink these.
Use plastic or glass to ferment in – metal is no good for kombucha.
Some sediment (called “lees” may appear). This is normal. Either stir it up and add to your finished product, or use as the starter culture for your next brew.
Kombucha is anaerobic fermentation process, so it needs oxygen to keep the fermentation happening – cover with muslin and elastic band.
The Mother should start to reproduce new baby SCOBY’s which will look like thin transparent layers of film over the top of the large Mother.
Once the thin layer gets firmer you can tear is away from The Mother if you want to start a new brew or give one away or just leave them together and let them keep on growing. Happy Family!
If you do this, you will need to slowly increase the volume of tea and proportionate ingredients, otherwise it will ferment too quickly and could become vinegary.
If your Mother doesn’t grow a baby, be patient. If the Mother is viable, it should do, it just may take time.
This is normal for the first 1-3 days, if, however, after this time, it is still sinking, compost The Mother and source a fresh one, as it’s not viable.
Fermentation is not happening – be patient!
- Is your Mother sinking? It could not be viable and you may need to source a new one.
- If your Mother is floating, be patient. In cooler temperatures, it may take several weeks to turn acidic.
- Was your water chlorinated? Was it reverse osmosis? This could inhibit fermentation. Use filtered or spring water for best results.
My kombucha is so sour!
Your ferment went too long – it’s still fine to drink, use it as a vinegar shot, or add some sweet fruit juice to it.
My kombucha is so sweet!
You harvested it too soon. Put it back on to ferment for several days or weeks until it has that distinctive sourness to it.
What if I go away?
Make a strong sugar: tea solution and put your Mother in the cool mixture. Place in a sealed container. It should be ok for up to three months in the fridge.
This is the recipe for the resting Mother:
- 500 ml water
- 1 cup sugar
- 4 black teabags
Add around 250ml boiling water to the tea bags. Steep for a minute or so. Discard tea bags. Add the sugar. Stir to dissolve. Top up with 250ml cold water.
Once the mixture is cool, add The Mother. Place in the fridge.
How to know if your Kombucha is ready for bottling?
It should have a vinegary acidic smell. You will defiantly notice a change from sweet to sour.
You should see small bubbles on the side of the glass of the fermentation vessel. You may also see bubbles pouring up from the bottom of the glass to the top. The Mother should be floating at the top of the fermentation vessel and could have a few bubbly foamy bits.
Generally kombucha fermentation does not have the bubbling sound, so tune into your sense of taste and smell.
There should be a lingering tea aroma with a sour and vinegary taste, sometimes a slightly bitter after-taste. A “young” kombucha will still have a sweetness to it, and be very fizzy after secondary fermentation, whereas a “mature” kombucha will be a quite vinegary tasting – but still great to drink!
TIP: You will need to source a kombucha SCOBY – you can find these here.
This blog is based purely on my personal experience. It is not intended to be a substitute for medical advice or treatment. I am neither a medical nor health professional and I cannot guarantee that the information in this blog post is accurate, reliable or complete. If you use this information, you do so at your own risk and should consult a qualified medical or health practitioner before relying on any information contained in this blog.