Experimenting with Kombucha


That's my first scoby in the making. I later killed it in an experiment, but I was proud to get it this far.

I never thought I’d want to brew my own kombucha (buch). I’m an avid water drinker, sometimes having a nice decaf green or herbal tea or indulging in hot chocolate. I don’t like carbonation, caffeine gives me palpitations, and I don’t want to drink my sugar—all things kombucha, in part if not in all. I liked the health benefits, but I didn’t consider it worth the trouble when I could just buy an occasional bottle I’d sip off over the span of a couple of weeks. Then I talked to a friend who continuously brewed her own kombucha and started reading about it and learned I could potentially brew kombucha without any of those things—like sipping vinegar! With all the benefits of um beneficial bacteria and none of the things that I don’t enjoy. Now my kitchen looks like a chemistry lab, or at the least, something that belongs to someone who’s way too into chunky sweet tea in random jars. Want to learn the basics? Here's a good user-friendly page to start: https://www.kombuchakamp.com/how-to-make-kombucha-complete-video-series

There’s a wealth of home kitchen blogs (like mine) that have at least one kombucha post, so how could I not add my own? Here are the basics for those of you just learning about the craze, but basics I haven’t seen on other food blogs:

Scobys need nutrients that come from camellia sinensis—tea. Scobys also need fuel—in this case, sucrose, breaking it down into its fructose and glucose parts, “eating” the glucose, and producing carbon dioxide and ethanol [alcohol]; the bacteria supposedly also turns the ethanol into healthy amino acids, vitamins, and minerals).

A more detailed look—
A quick camellia sinensis breakdown
Whether a tea is green or black determines on their oxidation level, achieved through varying processes. Green tea is steamed and doesn’t go through the same withering and oxidation process. It retains a maximum amount of polyphenols and volatile organic compounds. It’s traditionally sun dried, or basket, charcoal, or pan fired. Modern methods use oven drying, tumbling, or steaming. Green tea leaves are refired throughout the refinement process to improve shelf-life and flavor. Black tea comes from leaves that are withered, rolled, fermented, and dried. White tea just comes from young, usually minimally processed leaves. All these teas will deliver the nutrients a healthy buch batch needs.

Don’t use teas with volatile oils—peppermint, lemon balm, citrus peel, essential oils, etc.—these oils float to the top of the tea and can smother/suffocate the scoby, which needs oxygen. You can use decaf/lowcaf tea. Some brewers claim a scoby needs caffeine to thrive. According to an interview with Michael Roussin (http://www.phoenixhelix.com/2013/03/25/kombucha-myths-vs-truths/), who put a lot of his own time and money into trying to science up some kombucha truths, kombucha does not need caffeine to thrive. Also contrary to nonscientific claims, caffeine is not reduced during brewing/fermentation. You brew your initial tea with less caffeine (six to eight tea bags to a gallon as opposed to sixteen to twenty-one bags). If you use decaf tea, some people recommend using tea decaffed by the carbon dioxide or the water methods, not chemically, which uses the chemical solvents methylene chloride or ethyl acetate to remove caffeine. Methylene chloride has been linked to cancer in lab animals who inhaled it, but there’s no evidence of the same carcinogenic effects on animals who consumed it. So I’ll leave it up to you what kind of tea you wanna pickle in a jar left open to the scary elements floating around your kitchen for a week or three.

Buch likes glucose:
Kombucha yeasts need sugar (aka sucrose, which is made of fructose and glucose) for food, and it turns that into alcohol, which is food for the kombucha bacteria. In general, most fruit sugars are about half fructose and half glucose, and glucose is easier food for buch yeasts. So yes, you can brew kombucha without refined/white sugar. The closest you can get to totally eradicating sugar from kombucha is to let the yeast eat it all up, effectively turning the brew into kombucha vinegar, which is totally hella sour. Using alternate sugars increases the risk of contamination because the slow fermentation as your scoby adjusts to its new food source keeps the ph high for a longer period during the initial brew, i.e., acidity remains low, where high acidity helps prevent contamination from mold and pathogenic bacteria.

Table sugar is made of glucose and fructose, and kombucha yeast eats the glucose, usually leaving fructose behind. Using corn syrup, which is all glucose, could mean the yeast eats all of it up, leaving no other sugars behind, but apparently, no one’s pulled out their hydrometer to test this out.

What’s happening in that jar?!:
The standard buch brew, which calls for a cup of sugar per gallon of sweet tea, leaves 4 teaspoons (16 g) of sugar per 8 oz cup after a 7-12-day fermentation.

During the first week of first ferment, scoby yeast is using minerals in tea to produce enzymes that separate sugar into glucose and fructose, and no sugar has been consumed at that point. By the 15-day mark, the yeast is just starting to consume the glucose, and there are still 3.3 teaspoons of sugar left. It’s sour because of the acids formed.

What’s in it/isn’t in it after all that sittin’ around?:
The strandy things hanging off your scoby like jellyfish tentacles are strands of yeast. Yeast will also settle at the bottom of your jar like sediment or just float around like…well, like floaties. The bacteria you can’t see with the naked eye, but its responsible for building the cellulose scoby body. A big, meaty scobyloney is thanks to healthy bacteria.  

A healthy brew smells halfway between sweet tea and vinegar. Anything off from those smells might mean your kombucha is…also off.

ph will drop during a correct fermentation, becoming more acidic. Hooray! This acidity will make your brew more resistant to mold or pathogenic bacteria. It’s part of why you add starter liquid to your first ferment. Ideally, buch brewers recommend a ph between 3.2 and 2.5. You can find ph strips or an electronic ph meter from drug stores to check your numbers.

I’d read in no fewer than a dozen sources that new kombucha brewers shouldn’t worry so much about mold because it’s very, very, very rare. BEHOLD! I made the rare. Scobyloneys will generate all manner of oddities, but it's the dry, fuzzy oddities that determine a fail--fuzz is spores. And when the hyphae wave hi, it's time to say bye.

Sadly, my first scoby was down in that sweet tea, mothering this brew, and I had to toss it along with everything in this jar.
This was a low-caffeine (rooibos and decaf green with a couple satchels of black tea to feed the scoby) I was hoping would work since my first batch of all black tea turned out so well (and gave me my first scoby, which is now in the garbage). Luckily, I have a few extra to experiment with.

My very first batch, started Christmas Eve after a friend gave me my first scoby, was all off-kilter with the ingredients, but it went off almost perfectly, without a hitch, though it took about 17 days to get it where I wanted. I’d used too many black tea bags, too much sugar, and I never turn the heat on in my apartment, so it was cold. Still, everything was great. I split that first batch into two jars—one to second-ferment with some slices of Bosc pear (in the fridge because I was paranoid about leaving it on the counter for a week) and one left plain—and started my second batch—a low-caf experiment—before leaving for Mexico.

Your brew will change color during fermentation if you’re starting with a dark tea, lightening as yeast and bacteria happily consume and convert the tannins.

Brewers duke this one out: kombucha forms either glucuronic acid or a synergist, keto-gluconic acid, which helps the liver produce glucuronic acid.

It does not contain hyaluronic acid or glucosamine, though it might contain elements that help form them.

Kombucha does contain at least one beneficial yeast, an acetobactor (beneficial bacteria), gluconic acid (pH regulator), and acetic acid (antimicrobial acid that stabilizes blood sugar). There’s debate as to whether it contains glucuronic acid (https://www.gaiaresearch.co.za/kombuchaglucuronicacid.html), which reportedly binds toxins in the liver, contributing to its health, and carries them out through the kidneys. Some kombucha can contain compounds that possibly act as analgesic, anti-arthritic, anti-spasmodic, or liver protective, and antibacterial.

Kombucha contains 0.5 to 3 percent alcohol, depending on fermentation length. Beer contains 4 to 6 percent. Single-fermented buch contains the least, and a second fermentation will increase it. Store-bought can contain more because it continues to ferm on the shelf, though regulations now require manufacturers to retard fermentation, which often means pasteurization, which limits the drink’s benefits.

What else to use and do:

Vinegar all the things. There's white distilled vinegar in that spray bottle. If' it's touching any part of my process, it's vinegared, and that includes my hands.
Filtered water is best with scoby health and sanitation in mind.

Plastic can leach into your buch, and metal can corrode and harm the scoby, so stick to glass containers. A wider jar diameter will grow a larger scoby more quickly, i.e., brew a faster buch.
Make sure tea is cooled to room temp before dumping your starter tea and scoby in it.
Take your starter tea from the top of the jar where there’s both a good amount of yeast, which lives all through the buch but accumulates in greater concentration at the bottom of the brew, and healthy bacteria, which is where most of the beneficial bacteria lives.

It needs airflow, so don’t put it in a cupboard, and definitely don’t cover it tight. Most brewers use a tightly woven cloth cover secured with a rubber band, especially to keep out fruit flies, which will lay eggs on your scoby, and while seeing something resembling planarians crawling across a scoby is horrifically fun, and you can supposedly just wash those prepupae off, just NO. Rubber band that sh*t, ffs. But really, the only real reason I’ve found to toss a batch, scoby and all, is if you get mold. But who DOES that??

It thrives at 72-85 degrees, and temps in the 90s will eventually kill your scoby while the 60s will put it to sleep.

While you don’t need to follow standard recipes to brew buch, if you’re using low or decaf tea or sugar that isn’t sucrose, and you aren’t producing scobys like mad, you can give your scoby a rest by storing it in a “hotel” stocked with regular sweet black tea. Switch scobys out, and you’ll always have a ready supply for experiments. 

Here's a scoby progression from jellyfishy to scobyloney:

Half-inch scoby--good thickness for a new scoby, but the brew can finish (reach desired sourness/doneness) before it gets this thick. The "tentacles" are strands of Cthulu. I mean yeast. Perfectly normal.

Is there a lot of crud at the bottom of your buch? That’s normal. But if there’s a lot and your buch is cloudy while it should actually be getting lighter as it ferments, you might have too much yeast. It’s too warm, or there’s too much sugar, or both.

Is your newly forming scoby looking a bit thin? Bacteria produces the cellulose that forms the bulk of your scobyloney. It might be too cold or your brew might not have enough tea nutrients for your bacteria. There might be too much yeast; make sure you draw your starter tea from the top of your previous buch batch, where supposedly there’s a higher concentration of bacteria. Your mother scoby, which you slip into a new brew to introduce the cultures necessary to start fermentation, might be tired and need a rest in your scoby hotel.

This is my first scoby hotel--a glass tupperware with plastic lid. My friend gave me a big pickle jar filled with a bunch of her scobys, so now I have two scoby hotels.

Your first fermentation is bubbly/foamy. It’s alive! No, really—it’s giving off carbon dioxide, which is healthy. However, if the gas is lifting your new scoby out of the brew, just duck it back down so it’s back on the water where it belongs. It doen’t necessarily have to be at the top.

It’s too sour to drink! Add sugar, then. Just kidding—dilute it with juice or freshly brewed tea when you pour yourself a serving. I usually drink only half a cup a day, so I’m not exactly chug-a-lugging pints of this stuff on the regular. 
And other fun notes: 
Research all your questions, counter-research the answers you find, and if you’re going to experiment, take notes.

For each of my jars, I record the start and finish dates, contents, and notes. I labeled my jars (1 throught 6) and labeled each first-fermentation brew if I was doing a second fermentation on them (A, B, etc.).

Here are my current brews—note that ingredient quantities are adjusted to fit jar sizes, which are all between 1 quart and 1/2 gallon:

1. Start: 2/12/18, 3 bags red rooibos + 1 bag black tea
2. Start: 2/14/18, Finish 2/14/18, 3 black tea bags, half cup sugar; notes: slow, think, splotchy scoby, pretty sour, reserving as starter liquid for no-sugar and decaf/low-caf brews

These jars are perfect. The smaller one is 3/4 liters and the bigger one is 1 liter. These are brews 4 and 3 (left to right). 

3. Start: 2/12/18, second ferment of brew 1C (3 green, 2 black), 3/4 cup fresh tangerine juice, lid on to carbonate, 2 days on counter, fridge to continue ferment and store
4. Start: 2/12/18, second ferment of brew 1C, plain, lid on to carbonate, 2 days on counter, fridge to continue ferment and store

Jars 5 and 6. Scobys forming on fruit-only, full caf and decaf brews--this makes me happy because I wasn't sure if a sugar-free brew would work, especially the sugar-free decaf, but it's actually forming the better scoby. I used my friend's scobys because her setup is so well-established, and I used full scobys to hold the apple slices down because I worried leaving them exposed to air when they floated up increased their mold risk.
5. Start: 2/14/18, 2 black tea bags, half thinly sliced Fuji apple, full scoby, 1/2 cup 2B starter tea and some hotel buch
6. Start: 2/14/18, 2 bags decaf green, half thinly sliced Fuji apple, Holly scoby, 1/2 cup 2B starter tea and some hotel buch


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