Buying guide
Best Airlocks and Fermentation Lids (for Carboys, Jugs and Jars)
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Editor's Choice
FastRack 3 Piece Airlock (Set of 3)
The classic wine airlock at a budget price: a clear body, floating valve and cap that come apart for cleaning. FastBrewing lists it at 5.5 inches tall and top-rack dishwasher safe, and says it fits standard drilled stoppers and lids.
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Best airlock and bung set
FastRack Twin Bubble Airlock and Carboy Bung (2-Pack)
Two twin bubble airlocks and two bungs in one pack, so nothing else is needed.
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Best stopper for PET carboys
FastRack #10 Drilled Rubber Stopper (3 Pack)
The #10 size for large PET fermenters, with a 3/8 inch hole. Glass carboys that list a #7 need a #7 instead.
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Best stopper for glass carboys
Home Brew Ohio #7 Drilled Rubber Stopper (Set of 3)
A drilled #7 stopper for glass carboys whose listing states a #7, used with an airlock that is not included.
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Best lid for jars
Masontops Pickle Pipes Airlock Fermentation Lids
Waterless silicone one-way valves for wide mouth mason jars.
The best airlocks and fermentation lids are the ones that match the opening of your fermenter. A 3-piece airlock in a drilled rubber stopper suits a glass or PET carboy, a twin bubble airlock suits a 1 gallon jug or carboy, and a silicone fermentation lid suits a mason jar. All of them do the same job: they let carbon dioxide out and keep air, and so oxygen, from getting in.
Below we compare seven airlocks, stoppers and lids from FastRack, Home Brew Ohio, Masontops and Fermentaholics. We did not test them. We compared the published specifications from the Amazon listings and from the manufacturer's own store, and we say which source each number comes from. We also cover what to put in an airlock, when to fit it, and why bubbling is a poor clock. If you are still choosing the vessel the airlock goes on, start with our best carboys for wine.
Best Airlocks and Fermentation Lids Compared
Seven products, three types of fermenter. Details are the ones each listing states; "Not stated" means the listing does not say. Price tiers are market tiers, and all seven sit in the budget tier ($).
| Product | FastRack 3 Piece Airlock Editor's Choice | FastRack Twin Bubble + Bung | FastRack #10 Stopper | Home Brew Ohio #7 Stopper | Masontops Pickle Pipes | Fermentaholics Gallon Jar Lid | FastRack 1 Gal Fermonster |
|---|---|---|---|---|---|---|---|
| Product |  |  |  |  |  |  |  |
| Type | 3-piece bubbler airlock | Twin bubble airlock with bung | Drilled rubber stopper | Drilled rubber stopper | Waterless silicone jar lid | Gallon jar lid with S-airlock | Complete 1 gallon fermenter |
| Fits | Standard drilled stoppers and lids | Universal-fit carboy bung (size not stated) | Large PET fermenters; not carboys that state a #7 | Glass carboys that state a #7 | Wide mouth mason jars | Gallon jars, 110 mm (4.375 in) outer diameter | Built in |
| In the box (listing) | Set of 3; title mentions a drilled stopper | 2 airlocks, 2 bungs | 3 stoppers, 3/8 in hole | Set of 3; airlock not included | Pack size not stated; jar not included | Lid, gasket, grommet, airlock | Carboy, lid, #10 stopper, twin bubble airlock |
| Needs water | Yes | Yes | Not applicable | Not applicable | No (waterless valve) | Yes | Yes |
| Best for | Any wine carboy | Starting from nothing | PET carboys | Glass carboys with a #7 neck | Vegetable jar ferments | 1 gallon wine in a jar | Small trial batches |
| Price tier | $ | $ | $ | $ | $ | $ | $ |
| Buy | Check price on Amazon | Check price on Amazon | Check price on Amazon | Check price on Amazon | Check price on Amazon | Check price on Amazon | Check price on Amazon |
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Editor's Choice
FastRack 3 Piece Airlock
- Best for
- Any wine carboy
Show specificationsHide specifications
- Type
- 3-piece bubbler airlock
- Fits
- Standard drilled stoppers and lids
- In the box (listing)
- Set of 3; title mentions a drilled stopper
- Needs water
- Yes
- Best for
- Any wine carboy
- Price tier
- $
FastRack Twin Bubble + Bung
- Best for
- Starting from nothing
Show specificationsHide specifications
- Type
- Twin bubble airlock with bung
- Fits
- Universal-fit carboy bung (size not stated)
- In the box (listing)
- 2 airlocks, 2 bungs
- Needs water
- Yes
- Best for
- Starting from nothing
- Price tier
- $
FastRack #10 Stopper
- Best for
- PET carboys
Show specificationsHide specifications
- Type
- Drilled rubber stopper
- Fits
- Large PET fermenters; not carboys that state a #7
- In the box (listing)
- 3 stoppers, 3/8 in hole
- Needs water
- Not applicable
- Best for
- PET carboys
- Price tier
- $
Home Brew Ohio #7 Stopper
- Best for
- Glass carboys with a #7 neck
Show specificationsHide specifications
- Type
- Drilled rubber stopper
- Fits
- Glass carboys that state a #7
- In the box (listing)
- Set of 3; airlock not included
- Needs water
- Not applicable
- Best for
- Glass carboys with a #7 neck
- Price tier
- $
Masontops Pickle Pipes
- Best for
- Vegetable jar ferments
Show specificationsHide specifications
- Type
- Waterless silicone jar lid
- Fits
- Wide mouth mason jars
- In the box (listing)
- Pack size not stated; jar not included
- Needs water
- No (waterless valve)
- Best for
- Vegetable jar ferments
- Price tier
- $
Fermentaholics Gallon Jar Lid
- Best for
- 1 gallon wine in a jar
Show specificationsHide specifications
- Type
- Gallon jar lid with S-airlock
- Fits
- Gallon jars, 110 mm (4.375 in) outer diameter
- In the box (listing)
- Lid, gasket, grommet, airlock
- Needs water
- Yes
- Best for
- 1 gallon wine in a jar
- Price tier
- $
FastRack 1 Gal Fermonster
- Best for
- Small trial batches
Show specificationsHide specifications
- Type
- Complete 1 gallon fermenter
- Fits
- Built in
- In the box (listing)
- Carboy, lid, #10 stopper, twin bubble airlock
- Needs water
- Yes
- Best for
- Small trial batches
- Price tier
- $
Airlock and Fermentation Lid Reviews
Each review sticks to what the listing and the manufacturer's store say. The picks run from a basic wine airlock to a complete one gallon fermenter.
FastRack 3 Piece Airlock, Set of 3 (Editor's Choice)
The listing calls the bubbler style the go-to winemaking airlock, and a set of three covers a carboy, a spare and a second batch. It describes a transparent, food-grade body that lets you see the whole fermentation, and says it can also be used for sauerkraut and kimchi. FastBrewing's own store lists its 3-piece airlock at about 5.5 inches tall, made of three parts (a body, a floating valve and a cap) that take apart for cleaning, and dishwasher safe on the top rack.
The Amazon title mentions a drilled rubber stopper, but the feature list never says one is included in each set, so check the box contents before you rely on it. FastBrewing says only that it fits "standard drilled stoppers and lids", with no stopper size given.
Best for: glass or PET carboys with a drilled stopper. Missing: a stopper that you can confirm from the listing.
FastRack Twin Bubble Airlock and Carboy Bung, 2-Pack (Best Airlock and Bung Set)
If you are buying from scratch, this is the simplest set: the listing says you get two twin bubble airlocks and two universal-fit carboy bungs, for beer, wine, mead or kombucha. The airlocks are made of food-grade transparent plastic, and the listing says the airtight design helps prevent oxidation and releases pressure automatically.
You fill the airlock with water, and the listing says to insert the assembled airlock into the hole of the stopper. The Amazon listing does not give the bung size. FastBrewing's own store lists its twin bubble airlock at about 6.5 inches tall, so measure your carboy or jug neck and check the headroom before you rely on it.
Best for: a first fermenter, or two small batches at once. Missing: a stated bung size.
FastRack #10 Drilled Rubber Stopper, 3 Pack (Best Stopper for PET Carboys)
An airlock does nothing without a stopper that seals, and our carboy guide notes that FastBrewing says its PET carboys need a #10. This is a 3 pack of drilled #10 stoppers with a 3/8 inch center hole for standard airlocks, a tapered shape and a lip that stops the bung from falling into the carboy. The listing says the rubber is BPA-free and lab-grade natural rubber.
The listing contradicts the carboys, so go by the carboy. Its title says it fits large PET plastic fermenters, while a bullet says it is compatible with 3, 5, 6 and 6.5 gallon glass carboys. FastRack's own 5 and 6 gallon Italian glass carboy listings say their opening fits a #7, and FastBrewing's PET carboy pages say #10. FastBrewing's glass carboy pages give no number. So buy this one for PET, and buy a #7 for a FastRack glass carboy. If your carboy lists neither, measure the neck.
Best for: PET carboys, including the ones in our carboy comparison. Missing: the airlock itself, and any fit for #7 glass necks.
Home Brew Ohio #7 Drilled Rubber Stopper, Set of 3 (Best Stopper for Glass Carboys)
This is the #7 answer to the PET pick above. The listing sells a set of 3 white rubber stoppers, drilled so an airlock can sit in the hole, and says they are used in fermentation together with an airlock, which is not included. It is the size to look for when a glass carboy lists a #7: FastRack's 5 and 6 gallon Italian glass carboy listings say their opening fits a #7.
The listing does not state the hole diameter, so check that your airlock stem fits before you buy, and measure the neck if your carboy lists no number. Our search turned up several other drilled #7 sets at similar prices, and this one is a plain set of rubber stoppers with no extras.
Best for: glass carboys that state a #7. Missing: the airlock itself, and the hole size.
Masontops Pickle Pipes Airlock Fermentation Lids (Best Fermentation Lids for Mason Jars)
These are one-piece silicone caps with a one-way, waterless valve, made for wide mouth mason jars (the jar is not included). The listing says the valve vents gas by itself with no water, no burping and no maintenance, the silicone is BPA-free and phthalate-free, and the caps go in the dishwasher.
Read the use case carefully. The Amazon listing is written for sauerkraut, pickles and kimchi and never mentions wine, so treat these as a vegetable-ferment lid. For a gallon of wine, the next pick is a better fit. The listing does not state the pack size in the title.
Best for: jar ferments and the kitchen counter. Missing: any statement that it suits wine.
Fermentaholics Gallon Jar Fermentation Lid with Airlock (Best Lid for a Gallon Jar)
This turns a glass gallon jar into a fermenter, and the title names wine, beer, cider and mead as uses. The listing says it is a white plastic lid with a silicone gasket, a black rubber grommet and an S-airlock, and that it fits jars with a 110 mm (4.375 in) outer diameter, the size the listing calls standard for most gallon jars. All parts are listed as food-grade and dishwasher safe.
Measure your jar before you buy: the listing says it fits "the majority" of gallon jars, not all. It is a low-cost way to try a 1 gallon recipe with a jar you already own.
Best for: 1 gallon recipes in a glass jar. Missing: the jar.
FastRack 1 Gallon PET Wide Mouth Fermonster with Airtight Lid (Best Complete 1 Gallon Fermenter)
Here the lid and airlock come with the fermenter. The title and bullets say you get a 1 gallon wide mouth PET carboy with an airtight screw-on lid, a #10 drilled stopper and a twin bubble airlock. The listing says the wide mouth and smooth, rib-free interior make it easier to clean than a narrow-neck glass carboy.
The listing calls it ideal for primary fermentation, which makes sense for a small batch of wine that needs the room.
Best for: trial batches and 1 gallon recipes. Missing: nothing needed to start.
How to Choose an Airlock
Three choices decide it: the airlock shape, the stopper size and the fermenter it will sit on.
3-Piece, Twin Bubble or S-Type
Wikipedia describes the top-mounted three-piece lock as the most popular form today, with other designs using a bulb or a chamber to allow a wider range of pressure equalization. The shape is mostly a matter of how easy it is to see, fill and clean. A 3-piece airlock comes apart for washing, and an S-type is a plastic tube. Virginia Cooperative Extension lists an "S" type plastic tube as the airlock in its home winemaking equipment list. Any of them works for wine, so buy the one that is cheapest where you shop.
Stopper Size and Hole
The airlock goes into a drilled rubber stopper, and the stopper has to match the neck of the fermenter. The rule is PET #10, glass #7: FastBrewing says #10 for its PET carboys, and the FastRack glass carboys in our carboy guide state a #7. The hole in the FastRack #10 stopper is 3/8 inch. If the stopper size is not stated, measure the mouth of the fermenter and compare, or buy the stopper from the same maker as the carboy.
Airlock Lids or Stoppers
A wide mouth fermenter such as a bucket or a gallon jar uses a lid with a grommet instead of a stopper. The grommet seals the airlock into the lid, and a gasket seals the lid onto the jar, which is how the Fermentaholics lid works. Our carboy vs bucket page compares the vessels these go on, and the wine making kits include the airlock and stopper in the box.
How to Use an Airlock on Wine
An airlock is cheap, and almost every failure is a setup mistake, not a bad part.
What to Put in It
Virginia Cooperative Extension's guide Wine Making for the Home Gardener (HORT-213) says the air lock is a plastic tube filled with the same metabisulfite and citric acid solution used to sanitize equipment. Wikipedia describes the lock as filled about halfway with water, with a sanitizing solution, usually sulfur dioxide or alcohol, sometimes added so that nothing is carried into the vessel if liquid is drawn back in. Whichever you pick, fill to the line, and top up when it evaporates. Our guide to using Star San covers the sanitizing step for the rest of the gear.
When to Fit It
The same VCE guide says the primary fermenter is covered with a clean cloth that permits air exchange during the first phase of fermentation, and that the wine is racked into a clean secondary fermenter fitted with an air lock. So the airlock goes on at the second stage, after you rack; see how to rack wine for the transfer. Some kit instructions differ and tell you to fit the lock from the start, so follow the sheet that came with your kit.
Do Not Use Bubbles as a Timer
VCE says that when fermentation appears to have stopped, meaning bubbles are no longer coming through the air lock, you should check the specific gravity. Bubbles only show gas leaving through the lock, and a loose stopper can leak while the airlock stays quiet. A reading with a hydrometer is the check that counts. If the numbers will not move, see stuck fermentation.
Fermentation Lids for Jars
Silicone and plastic jar lids are sold as fermentation lids for mason jars, mostly for vegetables. They are useful for small kitchen ferments, but they are a different job from a wine airlock.
Waterless Valves
The Masontops and Mfacoy caps use a one-way silicone valve that vents gas by itself, with no water to top up. That makes them tidy for a jar of sauerkraut or pickles on a counter. Their listings are written for vegetables, and neither one says it has been designed for wine, so we list them as jar lids and not as wine fermenters.
Lids With an Airlock
For a gallon of wine, a lid with a gasket, grommet and water airlock such as the Fermentaholics pick gives you a water airlock like the ones on a carboy. Its listing names wine and mead among the uses and gives the jar size it fits. If the jar is a different size, or you want to avoid hunting for a fit, the complete one gallon Fermonster above comes with its own lid, stopper and airlock.
Wine is for adults of legal drinking age. Enjoy it responsibly.