Sweet, sweet Kombucha... how do I love thee? Let me count the ways.
1) You're delicious.
2) Well, you're super delicious.
3) You infest my digestive system with groovy probiotics.
4) Supposedly you have a bunch of health benefits, but who
knows because...
5) You're delicious and that's why I drink you!
Kombucha is fermented tea. I could give you a history lesson on it, but I'd rather just get right to it. The description of "Mushroom Tea" is a complete misnomer. Those cream colored critters floating in the jar? They are SCOBYs; symbiotic colonies of bacteria and yeast. Now hold your ponies, don't freak out by the bacteria thing. We're talking beneficial bacteria, though home brewing booch does have the potential to go bad. But when you have a healthy SCOBY and a good routine, it's a beautiful thing. I thought I would share my method. I've been home brewing for a year and it hasn't killed me... yet. If anything, I'm as healthy as a horse and never get sick. I attribute that more to being vegan and having a clean diet though. I drink kombucha because it tastes good. And I brew my own because it's downright expensive to have a bottle a day habit! I'm also spoiled because I could never go back to commercial kombucha after making my own. Every time my husband and I buy a bottle, we are both totally disappointed. Commercial kombucha pales in comparison.
So first things first! I make a very strong green tea. I use a 5qt stainless steel pot, add 20 bags of green tea and 2 1/2 cups of organic sugar. I bring this to a boil, making sure the sugar has dissolved, then let it cool. The tea needs to be approximately the same temperature as your brew so you don't harm your SCOBY.
I reuse old GT's bottles for my brew, but you can use anything that is lead-free. Mason jars, old wine bottles- whatever you have handy that you can stick a lid on. Some brewers like to use Grolsch bottles with the swing top lids, which I did try a couple times. I ended up returning to GT's bottles. Beer brewing shops have bottles that you can buy.
After a preliminary rinse with water, I fill one bottle a third of the way full with white vinegar. I cap it, shake the heck out of it then pour the vinegar into the next bottle. Lather, rinse, repeat. If you are paranoid, beer brewing shops have a sanitizing rinse that you can use instead of white vinegar. I myself find myself leery of chemicals. I use white vinegar to clean my house, but that is a post for another time.
I place all the caps in a small bowl that I pour the white vinegar from the bottle cleaning into. I let the caps soak in the vinegar until I am ready to cap the new batch. The bottles are rinsed with water, and I make sure the neck and threads of the bottles are clean. I set them aside.
Next I prepare my flavorings for the secondary ferment. Secondary ferments both has advocates and naysayers. My first batches were flat and I read how using fruit and doing a secondary ferment encourages carbonation. However the naysayers claimed that secondary ferments are dangerous and bottles have exploded on them. This is why my secondary ferment takes place in an ice chest. I have never had a bottle burst.
My preferred flavorings are sliced, fresh ginger with dried goji berries. Ginger is pretty reknowned for it's ability to cause fizz. In fact, I have achieved so much fizz from too much ginger that I've nearly lost half the bottle of my sweet nectar. Which makes me cranky! I peel the ginger and slice it into the size of quarters. Maybe an 1/8 of an inch thick. Sometimes I use two slices when I feel like living on the edge. I put about ten goji berries in each bottle and I'm ready for business.
Now is time for the SCOBY removal. I use a large bowl that I have sanitized with vinegar. Everything that comes in contact with the booch gets a vinegar dip and water rinse. Every time a batch of kombucha is made, a new SCOBY (or mother) is formed. The top layer is the newest baby. In the top picture you can clearly see four SCOBYs. If you are a groovy person, you will gift someone in need with one of your babies and a cup of starter fluid (your kombucha) so they can share in your obsession. I place the SCOBYs in the large bowl with a cup of starter fluid. Cover and set aside.
This is my basic setup for bottling. I've read that you should never use metal with kombucha, just like you need to make sure it doesn't come into contact with leaded glass. Apparently it can leech undesirables into your brew. No bueno! Using a metal pan to make the strong tea is permissable however. I use a strainer with plastic meshing to catch the yeast die off, which is perfectly safe to drink but it grosses Jay out so I strain it. I do use a towel over the counter just in case I dump a bottle. I use a plastic pyrex type measuring cup, pour into the strainer/funnel and fill to the top thread of the bottle. Less air in the bottle equates into more bubbles.
Once all of the bottles have been filled, give the caps a rinse with water and seal those bad boys. Stick them somewhere for their secondary fermentation. I keep my ice chest in the bedroom.
Now you need to clean your brew jug. FYI, I use a two gallon jug that came from Target. I researched online to make sure it was lead free. I rinse with water, then use the vinegar from the caps to swish about in the jug. If you have a lip, make sure you give that a good scrubbing with your fingers. SCOBYs sometimes like to crawl. After a final rinse with water, you are ready to add your strong tea.
A note on tea: you can also use black, oolong, green, red or white. Make sure the teas don't have essential oils added to them, such as lemon. Herbal teas also will not work for making kombucha. I prefer all green. And of course, being vegan, you will want to use organic sugar to ensure that it hasn't been filtered with bone char. Not to mention beet sugar can be a GMO, which I avoid like the plague.
You've probably noticed that bit of tape on my jar and wondered, "What the heck?" That is a marker so I know how much water (I use RO/DI water) to add to my strong tea. Then I add the starter fluid I had reserved with my SCOBY. I give it a good stir with a wooden spoon and add the SCOBY. What little starter fluid I have left, I pour on top of the SCOBY. I cover with a piece of cotton (old shorts that had become somewhat scandalous with holes), rubber band to secure then stick a skirt I sewed over the bottle to protect my brew from light. You could wrap it with a towel if you want, but if it's going to be in a dark place it should be fine without. I let my kombucha brew in the oven with the oven light on. Keeping the temperature around 80 makes the kombucha happy. Some use seedling mats to keep things warm.
I ferment for ten days, and my secondary ferment also lasts ten days. You can use a straw to taste test. Stick the straw in the brew, place your finger over the end and pull out. If it's too sweet, let it go longer. If it's too vinegary? You may have to scrap that batch and start over. You can still use the SCOBY and starter fluid however.
You can find many more in depth resources about brewing kombucha, including sites that help you identify problems with your brewing process. When I first began I was pretty darned paranoid about my SCOBY having mold as well as a myriad of other things. "Kombucha KommUnity" is a site that I visited fairly religiously as a beginner.
Do your research and jump into the pool. I assure you, the water is fine!