7th July, 2020
It’s somehow both scientific and sensual. I thrill in the flesh-like slipperyness, its living texture, its raw, vinegared smell, wondering if, perhaps, it likes to be touched. I let it slip through my fingers, back into the jar of cold tea that comprises both its habitat and sustenance, and replace the cotton cloth, like a Berber turban, over the mouth of the jar. The pellicle settles comfortably on the surface.
“Don’t give me that look.” I tell it – or her, for she is a mother, after all. “Not yet.” I shut the cupboard door, returning her to the darkness she requires to do her work.
By the next morning dark strands have formed, dangling from her underbelly. She looks like something between a fungus and and a pickled jellyfish – as fascinating as she is repulsive. The culture is not named Medusomyces for nothing – literally, ‘Medusa Mushroom’.
Like many of the more refined vices, it’s an oriental invention: a Manchurian medicinal concoction of black tea, white sugar, yeast and bacteria. It has been brewed continuously since at least 220 BC - a testament to its popularity - and over the last few decades has developed a coterie of devotees in the West – Kombuccaneers, if you will, into whose ranks I have taken my tentative first steps.
I have never tried it. Come to think of it, I had never even heard of the stuff until a week ago, although I'm told in certain university towns throughout country, commercial brews are gradually becoming as fashionable and available as craft beers.
Kombucha is renowned for its supposedly curative and invigorating properties; this slightly caffeinated, slightly alcoholic, slightly effervescent, fermented sweet tea is widely consumed as a peptic aid and probiotic, as well as for its uplifting effects on one’s mental well-being. Hearing people talk about it calls to mind the way people talked about tea in the 17th Century – a kind of medicinal tonic, with the power to restore the nerves, to ‘comfort and exhilarate’, as well as to indefinitely prolong the drinker's lifespan. The similarities are hardly surprising, considering that the two drinks are essentially the same substance, albeit in two very different forms.
Unlike the simple domestic yeasts used in the making of bread and beer, Kombucha requires the cooperation of two different microorganisms – a Symbiotic Culture of Bacteria and Yeast ('SCOBY' to those in the know). Together these life-forms weave a buoyant mat of cellulose – known as a pellicle or, to use a deliciously squidgy word, zoogloea. This is the ‘mushroom’ usually found floating at the surface of the brew.The zoogloeal island helps to protect it from invasions by feral bacteria or moulds which might threaten the sanctity and sterility of its home. Meanwhile, under the surface, its various yeast species gorge themselves on sugar and tannins preset in the tea, producing alcohol, which the surface-dwelling bacteria, in turn, oxidise into acetic acid, among other substances.
Since most of the sugar is converted to alcohol, and most of the alcohol is converted to acid, the end result is something that is neither particularly sweet nor particularly alcoholic. In fact, the longer one leaves the culture digesting, the more vinegar-like it becomes. Second and third fermentations in sealed containers will increase its alcohol content and effervescence, while fruit juice and other after-the-fact additions can create interesting variations in flavour. All in all, it is an incredibly fast process, capable of creating drinkable Kombucha from raw tea in as little as three days, under the right conditions.
My own brewing attempt appears to be taking its sweet time. I have two jars - one containing a Kombucha mother, the other housing her Tibetan cousin, Jun. The main difference between them is that Jun subsists on a diet of green tea and honey in place of black tea and sugar, making it perhaps even more wholesome. It's often referred to as the 'Champagne of Kombucha', on account of its subtler flavours and more vigorous fizz. I am keen to try them both, but at a paltry 19°C, which seems to be the ambient temperature in the cupboard I have dedicated to brewing, the cultures are agonisingly sluggish.
HOW TO BREW KOMBUCHA
I. Sterilise your brewing vessel and with scalding water. Do not use any bactericidal sprays or you will poison your culture.
II. Prepare your tea. Any quantity of starter culture will work with any quantity of tea, but while the bacterial colony is growing it is perhaps better to start with a small amount, especially if you don't have a pellicle yet. Use two liters of water with eight tea bags (you can scale this ratio up or down as required). Do not leave it for more than ten minutes, or you will have an excessive quantity of tannins, which can give the brew a bitter flavour.
III. While the tea is hot, stir in 160g to 200g of sugar, depending on your tastes. If you are making jun, allow the tea to cool before you stir in the honey or it will denature and lose much of its nutritional value.
IV. Let tea cool completely to room temperature. You may put it in the fridge or freezer, wrapped in a damp cloth if you wish to expediate this process.
V. Once the tea has no warmth whatsoever left in it, add your starter culture.
VI. Place your brewing vessel in a dark place with consistent temperature, preferably around 23°. Fluxuations in temperature or cooler conditions will retard the fermentation.
VII. After seven days, begin to taste your kombucha. Day by day it will lose sweetness and gain acidity until it eventually becomes vinegar. It is 'finished' at the point when you think it most paletable. Note that jun seems to brew a little quicker. Once it is done, you may drain it off, setting aside the pellicle and a small quantity of the culture for your next batch.
VII.5 You may then, if you so wish, decant the kombucha into round-sided, sealed bottles for secondary fermentation (F2). This will force carbonate the brew by ensuring that any CO2 produced by the yeast remains trapped in the bottle. At this point you may also add other flavours, such as fruit pieces or juice. Let them sit at room temperature for two to four days. After sampling a bottle to ensure it has reached the point you want it, put them in the fridge to stop them fermenting further (and prevent the bottles exploding). Note that if you want to try F2, it is better to draw your kombucha off while it is still slightly sweeter than you like it - this ensures that, after an extra few days of fermentation in the bottle, it will arrived at the sweet spot just in time.
IX. If you wish to brew again, you may set up another batch. Alternatively you could implement the continuous brew method, whereby you draw off kombucha whenever you wish to drink it, replacing it with a matching quantity of fresh, cool tea. This ensures 'perpetual' kombucha with a complex flavour and a thriving population of micro-organisms.
X. Your culture will eventually produce a pellicle at the surface, and your pellicle will eventually have children. In order to prevent space in brewing vessel being filled with zoogloeal islands, you may seperate the children from the 'mother' by peeling them apart. Extra pellicles can be accomodated in a 'SCOBY hotel', which is essentially a collection of pellicles swimming in a jar kombucha, to be kept in a cool place. The pellicles can also be eaten, composted, fed to chickens, made into jerky or dog chews; even dried and treated to create a strong, translucent leather substitute. You may also eventually wish to replace the mother with one of her children to keep the brew healthy.
The wait has been worth it. My first taste of homebrew was every bit as interesting as I might have hoped. It tastes like sweet vinegar, slightly reminiscent of cider and slightly reminiscent of tea, with a subtle complexity greater than the sum of its parts. Having enjoyed a glass each morning for several days in a row, I can easily see it becoming a habit. It brings a sense of satisfaction, similar to the comfort found in cup of tea or coffee: a perfect fit for those odd moments in the day, between this and that, when you need a little something to perk you up.
The other benefit to it is, of course, that kombucha is easily made onboard a boat. With the vessels made ready for sea, it would be possible to voyage with it; since both of its ingredients can be found anywhere, take up little space and can be stored indefinitely, it could be brewed on a continuous basis using left-over tea from the kettle. With some arrangement by which it might be kept warm by proximity to the engine room, I can imagine it working out very well indeed!