I am blown away by how cheap it is to make Kombucha vs what they sell it for in the store. I make 5 gallon batches, and average a few dollars per batch. The only ingredients are the Scoby (free after your first batch), black tea (40 bags per 5 gallon batch, I get them for $1.99 for 100) 5 cups of granulated white sugar ($2.00, half of a 5 lb bag) and then whatever fruit juice you want to use. I use whatever I can get on sale that week, usually 8-16oz for around $1-$2. So for a max of $6 I can make 5 gallons of kombucha, with the store regularly charging $2.69 for 16 oz. Just for scale, I could make 40 16oz botlles with a 5 gallon batch, or what they would charge $108 for at the store, per batch! This is to date my most profitable hobby, just based on how fast myself and others around me go through kombucha.
I let this batch go for too long, and it is very acidic. Luckily, I have my extra strength ginger ale ale in another corny keg that really cuts the acidity. The sweetness from the juice helps too, particularly the beet/strawberry as neither of those is very acidic, but the black currant does less.
The carbonation is a little weak. I have noticed that kombucha takes significantly more work to carbonate than beer, so that is a learning process. I have 2 kegs side by side that I kegged the same day. One is the kombucha, the other a new england IPA that I described here: https://steemit.com/food/@how2s101/brewed-a-new-england-ipa-with-maple-sap-instead-of-water-great-results-am-definitely-willing-to-share-the-recipe-if-there-is-any The beer carbonated great in a week, while the kombucha is rather lackluster, both in the same conditions. I will probably up the serving pressure for the kombucha, as the last batch I did was at a crazy 25psi, and worked great.
If you have any questions about the kombucha making process, or want any pictures of my setup, just leave a comment and I'll get right back to you!