A half gallon jar isn’t going to be enough for anyone that likes to drink the booch, especially if you want to continuously brew it. We use a 2 gallon jar with a spigot and it’s working out just fine. You can buy a scoby from Amazon for like $6 or $7 bucks. Brew a blend of black and green tea, add 1 cup of sugar per gallon of water, let it cool to room temperature and put it in your jar and add your new scoby. In about a week you’ll have kombucha, which you can then transfer to airtight bottles, adding a bit of juice or sugar for flavoring and let it sit for another 3+ days for the second fermentation and then drink/refrigerate. To continuously brew, keep at least 20% of the kombucha in your jar and just add more sweet tea. You can extend the fermentation periods to experiment with taste. Kombucha brewing is suuuuper easy. Tons of instructions online. I’m currently using some kombucha blend of tea leaves from Amazon that was $14 something for 8 ounces. It’s just as good as a different kombucha blend I previously bought for like $21 ($18 with coupon) for 4 ounces. More expensive may not make much difference.
I prefer live SCOBYs but YMMV. Also, I use 2 1/2 g jar with a warming pad under it for consistent result.
Agreed this is too small for realistic use.