Best tea for kombucha

Kombucha is sweet tea fermented by a culture. The sugar is the food, and the tea is the rest of the diet — it supplies what the culture needs beyond sugar, and it decides most of what the finished drink tastes like.

Choosing it is simpler than the tea aisle makes it look, because one rule eliminates most of the options before you compare anything else.

It has to be real tea, with nothing added

Kombucha needs Camellia sinensis — black, green, white or oolong, all of which are the same plant processed differently. Two categories are the classic mistakes:

• Herbal “teas” are not tea. Rooibos, chamomile, peppermint, fruit infusions. They are leaves and flowers from other plants, and on their own they do not give the culture what it needs.
• Flavored and oiled teas. The bergamot-scented classics are what catch people out, because they genuinely are black tea — with an oil added. The oil is the problem: oils are antimicrobial, they sit on the surface, and a culture that lives at the surface does not appreciate either.

So: plain tea, loose leaf or bagged, black or green, with an ingredients list that says tea and nothing else. That single filter removes most of the supermarket shelf and most of the ways a first brew goes wrong.

Black or green

Black tea is the reliable default. It is the most heavily processed form of the leaf, it brews strong, and it is what most kombucha has historically been made with. A black-tea brew is darker, more tannic and more robust.

Green tea ferments faster and gives a lighter, floral, less tannic result that a lot of people prefer to drink. The common caution is that a culture kept exclusively on green tea over many cycles can weaken, which is why blends exist.

A blend is the usual compromise and is what most teas sold specifically for kombucha are: enough black to keep the culture robust, enough green to lighten the flavor.

Note the herbal row. Herbal infusions are excellent in the second ferment, where you are flavoring finished kombucha in a sealed bottle. The rule is about the primary brew, where the culture lives.

How we judged these

1. Plain tea, nothing added. No oils, no flavoring, no herbal filler. Every pick here is tea and only tea.
2. Loose leaf over bags. Loose leaf is cheaper per brew, and bags bring staples, strings and sometimes the bag material into a vessel that will sit for a week.
3. Does the listing tell you what is in it? Most kombucha blends say “black and green” and stop. One here names both cultivars, which is worth something if you want to repeat a result.
4. Cost per gallon, not per bag. A pound of CTC Assam and eight ounces of a specialty blend are not comparable by price. One listing here publishes a yield, which is the only figure that makes comparison honest.
5. Quantity against how often you brew. Two pounds of tea is superb value and goes stale in a cupboard if you brew once a month.

Loose leaf or bags

Bags work. Plenty of people brew good kombucha with plain supermarket black tea bags and there is nothing wrong with it.

Loose leaf is cheaper per gallon, gives you a visible ingredient rather than a sealed paper packet, and avoids leaving staples and tags in a vessel for a week. It needs straining, which is a minor inconvenience against a brew that takes seven days anyway. If you are brewing by the gallon regularly, loose leaf is the obvious choice; if you brew occasionally, bags are fine and we are not going to pretend otherwise.

The rest of the setup

Tea is one of four inputs: tea, sugar, a culture and starter liquid. Plain white sugar is the standard feed — honey and most substitutes are not, for the primary brew. The vessel and cover are covered in brewing jars, and the whole setup is laid out in what you need to start brewing kombucha.

The short version

Buy plain loose leaf tea with nothing added. Start with a black and green blend if you want the decision made for you, or straight Assam if you would rather run one variable and adjust. Avoid anything oiled or herbal in the primary brew, and save the fruit and herbs for the second ferment where they belong.