Raw kombucha has to stay refrigerated because its culture is still alive and keeps fermenting, which changes the flavor and the fizz if it warms up.
Kombucha that has been pasteurized or sterile filtered no longer ferments, so it is shelf stable, and the Kombucha Brewers International Code of Practice says it does not need refrigeration.
Raw kombucha lives in the fridge because it is still fermenting. The yeast and bacteria that made it are in the can, and warmth wakes them up: the drink keeps getting more sour, and the carbon dioxide keeps building. Cold slows all of that down. Kombucha that has been pasteurized or sterile filtered no longer has a working culture, so it can sit on a shelf. Which one you are holding is printed on the label, in words the trade has defined.
| On the label | What it means | Storage |
|---|---|---|
| Raw | Not pasteurized, not sterile filtered, not chemically sterilized | Cold, 40 to 48 F |
| Pasteurized | Heated at some stage to kill the organisms; must be labelled | Shelf stable until opened |
| Sterile filtered | Filtered at 0.45 microns or finer, fine enough to remove the culture | Shelf stable until opened |
| Cold filtered | Filtered while cold, usually to take out excess yeast | Depends on the rest of the process |
| Unfiltered | Not filtered at all; expect sediment and strands | Usually cold |
What the trade standard says
The Kombucha Code of Practice from Kombucha Brewers International is the closest thing the industry has to a rulebook. It allows the word raw only when the kombucha has not been pasteurized, sterile filtered or chemically sterilized. Pasteurized product must say pasteurized. Filtration at or below 0.45 microns must be labelled sterile filtered, and gentler cold filtering, used to take out excess yeast, has its own term. On storage the Code is just as plain: raw kombucha should be kept between 40 and 48 degrees Fahrenheit through distribution, and shelf-stable product such as pasteurized kombucha does not need refrigeration.
Two brewers, two answers
Small brewers land on both sides. Boochy Mama's in Toledo keeps its kombucha unpasteurized and asks that cans be refrigerated, kept out of sun and never heated, with a date eight months from canning. Seattle Kombucha Company ships 12 ounce cans that its shipping policy calls shelf stable, needing no refrigeration, so they travel well by mail. Brew Dr. takes a third path common in larger plants: it chills its kombucha close to freezing, carbonates it in tanks and bottles it cold, then keeps it cold.
Neither choice is a sign of quality on its own. Raw kombucha keeps changing, which brewers who love a living product see as the point. Shelf-stable kombucha holds its flavor exactly as the brewer set it, and is far easier to get to people who live a long way from the brewery.
What it means when you pick one up
If the label says raw or unfiltered, pick it up from a fridge and keep it in one. Open it cold, and slowly, because a raw can that warmed up on the drive home may foam. Strands and a bit of sediment are pieces of the culture, and are normal. If the label says pasteurized or the brewer calls the can shelf stable, it is fine in a cupboard until opened, though it still tastes best poured cold.
Questions
Does kombucha need to be refrigerated?
Raw kombucha does. The trade's Code of Practice calls for it to be kept between 40 and 48 degrees Fahrenheit. Pasteurized or sterile filtered kombucha is shelf stable until opened.
What does raw mean on a kombucha label?
Under the Code of Practice, raw may only be used on kombucha that has not been pasteurized, sterile filtered or chemically sterilized.
How can I tell if a kombucha is pasteurized?
The Code requires pasteurized kombucha to say pasteurized on the label. Filtration at 0.45 microns or finer must be labelled sterile filtered.
What happens if raw kombucha gets warm?
It keeps fermenting faster. It gets more sour and can build more pressure, which is why brewers ship and store it cold.
