Bottling & carbonation
Most bottles are sold on adjectives. This one is sold on a number, and the number is the entire reason it keeps appearing on this site.
By Scooter M.·Published September 21, 2026
The short answer
Buy these if you are running a second ferment and want the one bottle on this site whose maker states what it can take: a published 100 PSI. Amber glass, a swing top that also accepts a 26 mm crown cap, sold by the case. The case price is the highest per bottle here, the swing-top gasket is a wear part you will replace, and nothing else about the bottle is documented.
This site has not pressure-tested a bottle and will not pretend otherwise. Testing a glass vessel to failure needs a rig and a safety cage, not a kitchen.
What this review does is take the figures EZ Cap publishes, hold them against the one job a kombucha brewer needs a bottle to do, and say plainly where the documentation stops. Everything below came from the maker's published listing and the live Amazon listing, read on 2026-09-21.
Finished kombucha goes into a bottle alive. The yeast keeps working on whatever sugar you added, the gas has nowhere to escape, and the pressure in the headspace climbs. That is the whole mechanism of a second ferment, and it is why the relevant specification for a conditioning bottle is pressure rather than capacity or looks.
Almost nobody publishes it. Across every bottle this site has sourced, the EZ Cap 16 oz amber is the only one with a stated figure: 100 PSI. Bormioli Rocco, IKEA and the generic amber cases publish nothing at all on the subject.
| Bottle | Closure | Pressure rating | Glass | Sold as |
|---|---|---|---|---|
| EZ Cap 16 oz amber | Swing top or 26 mm crown | 100 PSI, published | Amber | Case of 12 |
| EZ Cap 32 oz amber | Swing top | Not published for this size | Amber | Case of 12 |
| Bormioli Rocco Swing 1 L | Hermetic swing top | Not published | Clear | Single |
| IKEA KORKEN 1 L | Clamp stopper | Not published, not marketed for it | Clear | Single |
Read that table honestly and it is an argument about documentation, not about strength. A Bormioli swing top is a well-made bottle that many people condition in every week without incident. The difference is that if you ask what it can take, nobody at Bormioli has answered, and if you ask EZ Cap, there is a number on the listing.
Note the second row too: the 32 oz bottle from the same maker carries no published figure. The rating belongs to the 16 oz bottle, not to the brand, and it would be careless to assume it transfers.
The detail that gets overlooked: these accept both a swing top and a standard 26 mm crown cap. That is unusual and genuinely useful, because the two closures fail in different ways.
A swing top is reusable, instant, and depends on a rubber gasket that hardens with age and heat. Swing top gaskets and flat kombucha covers why a tired gasket is the commonest cause of a flat second ferment. A crown cap is a fresh, uniform seal on every bottle, and it needs a capper and a bag of caps — the three-part setup described on the crown cap page.
Owning a bottle that takes both means you can run swing tops for the weekly rotation and crown-cap the bottles you intend to leave for months, without buying a second set of glass. EZ Cap states its bottles are designed primarily to be crown-capped for long term storage, which is the maker telling you which closure it trusts over time.
The rated 16 oz case, and the hermetic swing top most brewers actually reach for when they want a single larger bottle rather than a case.
EZ Cap
The only bottle here with a published pressure rating — 100 PSI — in amber glass, which is the combination a second ferment actually asks for.
#ad Price as of October 18, 2026. How this is funded.
Bormioli Rocco
Italian soda-lime glass with a published height and diameter and a hermetic clamp seal — the bottle that looks like a bottle, with the dimensions to check it fits a fridge door.
#ad Price as of October 18, 2026. How this is funded.
Amber glass filters visible and near-ultraviolet light. A bottle conditioning on a counter for three days near a window gets meaningfully more light exposure than one in a cupboard, and light degrades both flavor compounds and the culture.
If your bottles condition in a dark cupboard and then go straight into a fridge, amber buys you very little and clear glass shows off the color. If they sit on a kitchen counter in daylight, which is what most people actually do, amber is doing real work.
A gallon is 128 oz. Hold back roughly ten percent as starter tea for the next batch and you have about 115 oz to bottle, which is seven 16 oz bottles with a little left over. A case of twelve therefore covers a gallon with spares in the wash, which is the arithmetic that makes a case the sensible purchase rather than an extravagance.
Sixteen ounces also chills faster than a liter and limits the damage if one bottle runs away. Kombucha bottle sizes works through the trade-off against 32 oz, which is really a trade-off between bottling effort and how fast an opened bottle goes flat.
On specification, this is the bottle to buy for a second ferment, and the reason is narrow and defensible: it is the only one whose maker will state a pressure figure, and pressure is the property that matters for this job. The dual closure is a real bonus, and amber is the correct glass for a bottle that conditions in daylight.
On value, it is the most expensive route per bottle here, and a case of twelve is more bottles than a half-gallon brewer needs. If you already own swing tops that have held pressure for a year without complaint, this page is not an argument to replace them. It is an argument for what to buy when you are buying anyway.
Heads up: some links on this page are affiliate links. If you buy through one we may earn a commission at no extra cost to you. It never changes a ranking, and we take no payment for placement. The full version.
Ranked on the published rubric. Every row jumps to that product's full write-up below; the button goes straight to Amazon.
| # | Product | Best for | Score | Price |
|---|---|---|---|---|
| 1 | EZ Cap Swing Top Bottles, Amber Glass, 16 oz (Case of 12) The only bottle here with a published pressure rating — 100 PSI — in amber glass, which is the combination a second ferment actually asks for. | Second ferment, one serving at a time | 8.3out of 10 | |
| 2 | Score7.8 EZ Cap Swing Top Bottles, Amber Glass, 32 oz (Case of 12) The same swing top and amber glass at quart size, which turns a gallon batch into six bottles instead of ten and roughly halves the bottling job. | Bottling a gallon in six moves | 7.8out of 10 | |
| 3 | Bormioli Rocco Swing Top Bottle, 33.75 oz (1 L) Italian soda-lime glass with a published height and diameter and a hermetic clamp seal — the bottle that looks like a bottle, with the dimensions to check it fits a fridge door. | A bottle you would put on a table | 8.0out of 10 |
#1 · Second ferment, one serving at a time
The only bottle here with a published pressure rating — 100 PSI — in amber glass, which is the combination a second ferment actually asks for.
Who it is for. Anyone doing a second ferment who wants a bottle with a number behind it rather than a shape that looks strong.
Source: MoreBeer published EZ Cap product specification (capacity, pressure rating, case contents, crown cap compatibility), morebeer.com/products/ez-cap-swing-top-bottles-amber-glass-16-oz-case-12, fetched 2026-09-01
Skip it if. You want to see the color of the finished drink. Amber hides it; the clear version of the same bottle does not.
#ad Price as of October 18, 2026. How this is funded.
#2 · Bottling a gallon in six moves
The same swing top and amber glass at quart size, which turns a gallon batch into six bottles instead of ten and roughly halves the bottling job.
Who it is for. An established brewer bottling a gallon a week who is tired of filling ten bottles.
Source: MoreBeer published EZ Cap 32 oz amber listing, same product line as the specified 16 oz, morebeer.com/products/ez-cap-swing-top-bottles-amber-glass-32-oz-case-12, retrieved 2026-09-01
Skip it if. You are new to second ferment. Learn what your kitchen does to carbonation in 16 oz bottles, where the consequences are smaller.
#ad No live price feed yet, so no number is shown rather than a stale one. How this is funded.
#3 · A bottle you would put on a table
Italian soda-lime glass with a published height and diameter and a hermetic clamp seal — the bottle that looks like a bottle, with the dimensions to check it fits a fridge door.
Who it is for. Someone bottling a lightly carbonated kombucha for the table, or storing finished kombucha in the fridge rather than conditioning it on a counter.
Source: Bormioli Rocco published Swing bottle specification (capacity, 12.13 in height, 3.5 in diameter, soda-lime glass, hermetic seal, care instructions), retailer specification listings retrieved 2026-09-01
Skip it if. You are chasing hard carbonation. Without a stated pressure rating, a bottle you are deliberately building pressure inside is a bottle you are guessing about — use the rated EZ Cap instead.
#ad Price as of October 18, 2026. How this is funded.
Every specification cited on this page came from one of these documents, retrieved on the date shown against the product it belongs to.
Bottles compared on published pressure ratings, closure type, glass color and size — and which bottles must never hold a second ferment.
Which swing tops publish a pressure rating, which are storage bottles wearing the same shape, and how to tell them apart before you fill them.
Why a second ferment runs away, the one bottle here that publishes a pressure rating, and the free tester-bottle habit that ends the guessing.
Why a perished gasket is the most common cause of a flat second ferment, how to test a seal in two minutes, and when to replace.
The three-part crown-cap setup compared against a swing top on published carbonation ratings, running cost and what fails first.
How many bottles a gallon fills at each size, and the real trade-off: fewer bottles to fill against faster loss of fizz once opened.