A Crash Course on Kombucha

• It's cheap. Cheaper than juice, soft drinks, or sweetened tea, my three default beverages.
• I like to have something to drink that's not water.
• It's a fun thing to make. It's a neat little project, much like homebrewing, but a lot simpler than many alcoholic beverages.
• By replacing most of my beverage drinking with kombucha, my refined sugar intakes have been reduced significantly, to the point that I've begun to notice the exceeding sweetness of soft drinks, and the effects of a “sugar high”.

Now, if you're sitting there thinking, “I want to get on this bandwagon!” here's your first step: gather the supplies. Most people recommended doing a one-gallon batch, and not going much smaller than that. (The smaller the batch, the more finicky the ratios of ingredients can be.)

• 2 cups of “starter fluid”. Commonly, people will tell you that you need a blob of cellulose that they call a SCOBY (Symbiotic Colony Of Bacteria and Yeast). In reality, the glob of celluose is a byproduct of fermentation called a pellicle, and isn't required, as long as you get a good amount of already-fermented kombucha (which is the real SCOBY). What you do need is 2 cups of unpasturized, "plain" kombucha. You can use some from a friend, or buy a bottle (just make sure it's "raw" and unprocessed).
• A 4 litre/1 gallon brewing vessel. The simplest method is to buy a pickle jar at Costco, and force your family to eat a lot of pickles. This can be glass or ceramic, but stay away from any plastics or metals.
• Tea. For the basic recipe, use black tea. You can also use green or white tea, but avoid flavoured teas, even Earl Grey, as they can have ingredients that will conflict with the fermentation process. If you don't like the “plain” end product or want more flavour variations, there's things we can do at a later step. For each batch, you'll need 7-10 tea bags, or 2-3 Tbsp of loose-leaf. Since caffeine is one of the things that the culture consumes, non-caffeinated tea is not an option. I have seen reports of caffeine tests saying that the end product has less caffeine than decaffeinated coffee, but it does vary.
• 3 litres of water, preferably with no chemical additives, like fluoride or chlorine. Some set their water out overnight, as they claim some of the fluoride evaporates, but I haven't researched this. I use city tap water and have noticed no issues.
• 1 cup of sugar. This can be white sugar or a less-processed version. Honey is also an option, but I wouldn't start off with that. Also, as the sugar is the other thing that the culture consumes, you can't use any fake sugars, even stevia.
• You'll need something to bottle the finished product in. You'll want something sealable and air-tight, and designed to hold pressure. (This means no mason jars!) The bottles I use are called swing-tops, and you can find them at homebrew supply stores. (Also, don't just use any bottle if you don't know how much pressure it can hold. IKEA sells swing-tops, but the aren't tested for pressure—I asked—and you risk having one explode!) While you're learning, you can reuse 1 litre soft-drink bottles, which also helps you learn how long it takes to carbonate (as you can feel how much pressure has built up), but apparently the long-term use of plastics can leach chemicals out of them. They also don't look very pretty.

Have all your supplies ready? Let's head over to step two: basic brewing. The basic process of making kombucha is very simple! Once you've got your supplies laid out, let's start. 

1. Boil half of your three litres of water. Once boiling, add the tea and steep for about 5 minutes.
2. Remove the tea and dissolve the sugar.
3. Add the remainder of the water. Before continuing to step four, you'll want to make sure your sweet tea is at room temperature, as high temperatures can kill the fermentation cultures.
4. Combine the sweet tea and starter fluid in your jar, then add your "starter fluid".
5. Cover with a cotton cloth (not cheesecloth as it's too loose) and let it sit for 7-10 days, at room temperature and out of the sunlight. In general, it'll go faster the warmer your home is, so if your house is cool, find a warmer spot. In winter months, I've brewed mine on top of my fridge, where it benefits from being higher, and also from the warmth generated by the fridge.
6. After about six days, stick a straw down past the newly forming pellicle, place your finger on top, and pull up a sample of the fluid. Do this each day until it has a combination of tartness and sweetness that you like, then move on to step 7.
7. Bottling day! Set aside two cups of the kombucha (the "starter fluid") and, if you want, your SCOBY/pellicle, for the next batch, then divide among your bottles. This is when you'd add flavouring items, detailed below. If you're not adding any flavouring elements, and you want strong carbonation, you could add a quarter teaspoon of sugar to fuel extra carbon dioxide production. You'll also start your next batch at this point, though you can wait a few days as well. (Your "starter fluid" will continue to ferment.)
8. Seal your bottles and keep them at room temperature for about 48-60 hours. This is called the second fermentation. If you're using plastic, you'll be able to feel them get hard as the carbon dioxide, one of the products of fermentation, builds up. Keeping the bottle sealed will trap that carbon dioxide, which will give you fizz when you finaly open it.
9. After 48 hours, it's ready to drink, or place in the fridge to slow the pressure build-up.

Instead of bottling 7/8 of your brew (step #7 above) you can also bottle less, replenish with a smaller amount of tea+sugar in the same proportions, and then the waiting period until the next bottling will be shorter. Some call this "continuous brewing" and it is what I do. I'm currently brewing 10 litres at a time, and I bottle 1.5 litres every 3-4 days.

When you bottle your kombucha for the second stage of fermentation, you can add a myriad of fruits, vegetables, and herb combinations to add to the flavour of the drink. The basic idea is, when you bottle, add some fresh or frozen fruit, fruit puree, pure fruit juice, or any combination, and see what happens. A basic rule of thumb is to use about 1/8 to 1/4 of a cup per 1-litre bottle.

Be careful when you open them for the first time! Just like adding sugar during the second fermentation, the sugars in your flavouring additives can cause some crazy over-carbonation if you're not careful.

Here's some of my favourite things I've used as flavouring:

• Goji berries
• Cherries
• Blueberries
• Ginger root (grated while frozen works best)
• Apples and cinnamon
• Molasses

Experiment! There's not much that can go wrong, other than you making a mess in the kitchen or making a strange flavour, like garlic and lemon. Have fun!