Choosing the right kombucha bottles + caps

Kombucha Basics: Bottles & Caps · Watch on YouTube

Quick refresher: F1 turns sweet tea into unflavored, largely un-carbonated kombucha (in these vessels); F2 is when you flavor and bottle it for around 3–4 days at room temperature to create carbonation. These are the containers for F2.

What to look for…

Good-quality, food-grade glass that's thick enough to handle high-pressure contents. And equally important: the cap. You want a cap that secures tightly enough to make an airtight seal — that's what traps the carbonation in the liquid as your brew ferments in the bottle.

What to avoid…

Poor-quality or thin glass can actually be dangerous in F2 if pressure builds too far. You're brewing a carbonated, living beverage — perfect consistency is hard — so if the glass can't handle it, you'll have a mess (or worse) on your hands. Keeping F2 bottles in a closed cabinet or cooler (without ice) contains any accidents (🎥 how to avoid bottle explosions). Still, steer clear of:

• Decorative, colored glass that's not meant to hold liquids
• Flip-top bottles from IKEA
• Square bottles — the shape handles pressure poorly and is more prone to explosions
• Recycled beer bottles (see the exceptions below)

Great option: flip-top bottles (a.k.a. Grolsch bottles)

These* are really common with home brewers, with good reason — some of the best bottles you can use for F2, with caps that make a really airtight seal. Downsides are minor: a little pricey per piece, and the flip-tops can be stiff to open at first (especially with joint pain) though they break in over time. You can get them with ceramic tops (nicer feel, same quality) or in 32-oz/liter sizes.

Great option: recycled store-bought kombucha bottles

Ange has recycled GT Synergy, Health-Ade and Kevita bottles, and they're fantastic for F2. The caps are what matter: do not remove the paper/plastic liners inside the cap — they're what holds carbonation in. Use rubber grippers to seal them up tight. (Lost the caps? See cap sizes below for compatible replacements. And here are tips on removing the labels.)

Great option: specialty bottles (stout, Boston round, ring-neck…)

Since Ange brews a lot, these are her favorites: the most choice in shape and size (8, 12, 16 oz and up), less bulky than flip-tops, and the cheapest option when bought in bulk from a wholesale bottle distributor. (🎥 Where Ange gets her specialty bottles)

Kombucha-brewer supply shops sell these online at a significant markup — buy in bulk yourself if you can. Online wholesale bottle stores price them low but shipping is high (it's glass!). A local wholesale distributor that sells direct to consumers is your best bet: inspect the bottles, test samples before committing, and pick up in person to save shipping.

No supplier in your area? Amazon options: 8-oz stout bottles and 16-oz stout bottles. Note Ange hasn't tested this brand/seller herself (she bought from a local supplier at a discount), so your experience may differ — and she can't confirm the included caps are the F217s she recommends. If you don't get a tight seal, try these replacement 38/400 F217 caps (also untested — if they disappoint, email youbrewkombucha@gmail.com so she stops recommending them!).

Bottle caps are super important!

A good cap keeps carbon dioxide from leaking out of your brew — you want all that fizzy goodness trapped in your drink. Two types suit most specialty bottles and work as replacements for store-bought kombucha bottles:

• Polycone seal caps — conical liner inside the cap. Lots of sites claim these hold carbonation best; in Ange's testing against basic F217s, there was no significant difference, and polycones usually cost much more. She skips them.
• F217 caps — plain-looking (usually black) caps with a barely-noticeable white liner: a thin foam core sandwiched between polyethylene layers ("F217" is the liner name). Her favorites: cheapest, hold carbonation fantastically when sealed tight (rubber grippers help!), and they double as a fizz gauge — once bottles are well-carbonated, the cap domes slightly upward. That's your sign they're ready to refrigerate. They flatten again once opened, and you can reuse them many, many times.

Iffy options

• Beer bottles. Ange experimented a lot with beer bottles, crown caps and a capper — she really wanted it to work (so cheap! so available!) but had a bottle break on her. Use at your own risk, in specific situations only: if you're flavoring without building carbonation, you can bottle in beer bottles and move them straight to the fridge. A day at room temperature is the most she'd risk.
• Mason jars. She wanted to like them, but couldn't get consistently fizzy results — too many flat batches, even with warmed, maximally-tight seals. Way more inconsistent than any other F2 container she's tried.

Dark vs. clear glass

It doesn't matter much. If your F2 bottles sit in direct sunlight, the sun's anti-microbial effects could slow or halt fermentation — dark glass adds safety there. But Ange keeps her second ferments in a dark cabinet while they carbonate, then straight into the fridge, so they barely see daylight. She prefers clear glass: you can see the flavors, and you can gauge how aggressive the carbonation will be before opening each bottle. (Yes, cabinets are fine for F2 even though they're wrong for F1 — sealed bottles can't pick up mold from their environment.)

On this page, you'll find some affiliate links to sources where Ange has purchased the ingredients/materials she uses. She may get a small cut of Amazon's profit for finding + recommending them to you — it won't cost you any more than you'd normally pay. She went through a lot of trial and error to find low-cost, high-quality options to save us all money. But feel free to purchase from wherever you like!