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Best airlock for homebrewing beer and wine: Amazon picks

Airlock style (three-piece versus S-bubble versus blowoff tube), whether the airlock is reusable, size of the stopper or bung needed for the fermenter opening, visibility of bubbling activity and ease of cleaning without disassembly determine which airlock suits beer and wine fermentation.

By Pickspry EditorialUpdated September 28, 20264 picks

The short answer

Three-Piece Twin-Bubble Airlock at $2 is the best airlock for most home brewers: the three-part design (cap, body, base) disassembles completely for thorough cleaning between batches, the clear plastic allows watching CO2 bubbles to monitor fermentation activity and the standard 7mm opening fits the most common drilled stopper sizes used with 6-gallon carboys and buckets.

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Quick picks

01
Best airlock for most home brewers
Three-Piece Twin-Bubble Airlock
Home brewers who want an airlock that disassembles completely for thorough cleaning between batches and provides clear visual confirmation of CO2 gas release during fermentation, where the three-piece design (cap with holes, inner cup, outer base) separates into three components for brushing and rinsing each part individually.
02
Best S-type airlock
S-Type Curved Bubble Airlock
Home brewers who want a single-piece airlock design with fewer parts to keep track of, where the S-type uses a single curved tube design with two water chambers in a continuous loop that does not fully disassemble, reducing the risk of losing separate cap or base components between brews.
03
Best airlock multipack value
Midwest Supplies 3-Pack Airlocks with Stoppers
Home brewers who want multiple airlocks and matching stoppers in a single purchase for use across multiple fermenters simultaneously, where Midwest Supplies 3-Pack includes three three-piece airlocks and three matching drilled stoppers that fit standard glass carboys and drilled bucket lids.
04
Best blowoff tube for vigorous fermentation
Homebrewing Blowoff Tube Kit
Home brewers using high-fermentability recipes (hefeweizen, Belgian ales, American wheat) or pitching large quantities of yeast that produce vigorous fermentation with krausen foam rising high enough to clog a standard airlock, where a blowoff tube replaces the airlock for the first 24 to 72 hours of fermentation by routing foam overflow out of the fermenter through a tube into a container of water.

How we chose

Airlocks are evaluated by style (three-piece versus S-type versus blowoff), disassembly for cleaning, stopper compatibility, visibility of fermentation activity, liquid requirement and price. Specs from manufacturer product pages. We did not test these products.

The picks, in detail

4 picks reviewed

Best airlock for most home brewers

Three-Piece Twin-Bubble Airlock

Brand: Generic homebrew supply

Best for

Home brewers who want an airlock that disassembles completely for thorough cleaning between batches and provides clear visual confirmation of CO2 gas release during fermentation, where the three-piece design (cap with holes, inner cup, outer base) separates into three components for brushing and rinsing each part individually.

Skip if

Simplicity with minimal parts to keep track of is the priority. Three-piece airlocks have three separate parts that can be lost separately. The S-type airlock is a single connected unit that does not come fully apart, making it less likely to lose components but harder to clean the interior water reservoir. For brewers who prioritize minimal parts, the S-type is appropriate.

Check price on Amazon

Three-Piece Twin-Bubble Airlocks use two interconnected chambers partially filled with sanitizer solution. CO2 produced by yeast fermentation bubbles through the liquid, releasing gas while the liquid barrier prevents outside air from entering. The three parts separate for cleaning. Standard sizing fits the #6 rubber stopper used with 6-gallon glass carboys and most homebrew bucket lids. Sold individually or in multipacks.

Three-piece airlocks are a generic homebrewing supply item produced by multiple manufacturers and sold under homebrew brand names.

At $2, the three-piece airlock is the most affordable individual airlock in this guide.

Specifications

Specifications for Three-Piece Twin-Bubble Airlock
Style	Three-piece (disassembles)
Stopper size	Fits standard
Fill liquid	Sanitizer or water
Visibility	Clear plastic, visible bubbles
Price	$2

Specs from Three piece twin bubble airlock homebrewing beer wine fermentation stopper, 7mm Amazon search

Best S-type airlock

S-Type Curved Bubble Airlock

Brand: Generic homebrew supply

Best for

Home brewers who want a single-piece airlock design with fewer parts to keep track of, where the S-type uses a single curved tube design with two water chambers in a continuous loop that does not fully disassemble, reducing the risk of losing separate cap or base components between brews.

Skip if

Thorough cleaning between batches is important. S-type airlocks cannot be fully disassembled for internal brushing. The interior of the curved chambers can be rinsed but not brushed. For brewers who have had contamination issues or who ferment under warm conditions where mold growth is a concern, the three-piece design that can be fully disassembled and brushed provides more thorough cleaning capability.

Check price on Amazon

S-Type Airlocks use a continuous curved tube loop with two water chambers. The design means the liquid path is always connected through the S-curve, providing dual water barrier protection. The S-type is the standard airlock in European homebrewing supplies and wine making. The airlock inserts into the same standard stoppers as three-piece designs. Fill the chambers to the indicated fill line with sanitizer solution.

S-type airlocks are a generic homebrewing supply item produced by multiple manufacturers.

At $2, the S-type is the most affordable single-piece airlock in this guide.

Specifications

Specifications for S-Type Curved Bubble Airlock
Style	S-type (single curved unit)
Stopper size	Fits standard
Disassembly	No (single piece)
Visibility	Clear plastic
Price	$2

Specs from S-type curved bubble airlock homebrewing beer wine fermentation single piece, stopper Amazon search

Best airlock multipack value

Midwest Supplies 3-Pack Airlocks with Stoppers

Brand: Midwest Supplies

Best for

Home brewers who want multiple airlocks and matching stoppers in a single purchase for use across multiple fermenters simultaneously, where Midwest Supplies 3-Pack includes three three-piece airlocks and three matching drilled stoppers that fit standard glass carboys and drilled bucket lids.

Skip if

Only one fermenter is in use at a time. A multipack provides more airlocks than a single-fermenter brewer needs. For brewers with one fermenter who want a single airlock plus a backup, buying individual airlocks at $2 each is more economical than a multipack. A multipack is most useful for brewers running two to three fermenters simultaneously for different batches.

Check price on Amazon

Midwest Supplies 3-Pack includes three three-piece airlocks and three #6 rubber stoppers. The stoppers are drilled to accept the airlock stem. The three-piece airlock design disassembles for cleaning. Running three fermenters simultaneously (two primary fermenters and one secondary, or three primary batches started on different days) is a common use case for the multipack. Midwest Supplies sells the pack through Amazon and their own site.

Midwest Supplies is a Minnesota homebrew and winemaking supply company established in 1993, one of the largest homebrew supply retailers in the US.

At $6 for 3, Midwest Supplies 3-Pack is the best value airlock multipack in this guide.

Specifications

Specifications for Midwest Supplies 3-Pack Airlocks with Stoppers
Quantity	3 airlocks + 3 stoppers
Style	Three-piece
Stoppers included	Yes (#6 rubber stoppers)
For	Multiple simultaneous fermenters
Price	$6

Specs from Midwest Supplies 3 pack airlocks stoppers homebrew fermenters beer wine, kit Amazon search

Best blowoff tube for vigorous fermentation

Homebrewing Blowoff Tube Kit

Brand: Generic homebrew supply

Best for

Home brewers using high-fermentability recipes (hefeweizen, Belgian ales, American wheat) or pitching large quantities of yeast that produce vigorous fermentation with krausen foam rising high enough to clog a standard airlock, where a blowoff tube replaces the airlock for the first 24 to 72 hours of fermentation by routing foam overflow out of the fermenter through a tube into a container of water.

Skip if

Standard lager or low-fermentability ale recipes are the normal brew style. Most standard homebrew recipes fermented at proper temperature and yeast pitch rates do not produce enough foam to clog a three-piece airlock. A blowoff tube is a precaution for recipes known to ferment vigorously, not a requirement for all fermentations. After the first 48 to 72 hours, the blowoff tube is replaced with a standard airlock for the remainder of fermentation.

Check price on Amazon

Blowoff Tube Kits use a 1-inch diameter flexible tubing with a drilled stopper on one end that fits the fermenter opening. The other end is submerged in a container of sanitizer solution. CO2 and foam blow out through the tube into the sanitizer container rather than clogging and potentially blowing off a standard airlock. After active fermentation subsides (CO2 bubbling slows significantly), the blowoff tube is replaced with a standard airlock for the secondary fermentation period.

Blowoff tubes are a generic homebrewing supply item used as a safety precaution during vigorous fermentation.

At $5, a blowoff tube kit is the best precaution for vigorous fermentation in this guide.

Specifications

Specifications for Homebrewing Blowoff Tube Kit
Style	Tube with stopper
Tube diameter	1 inch
Length	36 inches
Use case	Vigorous primary fermentation
Price	$5

Specs from Homebrewing blowoff tube kit 1 inch diameter stopper bucket glass carboy active, fermentation Amazon search

Airlock comparison

Product	Style	Disassembly	Quantity	Price
Three-piece twin-bubble	Three-piece	Full	1	$2
S-type curved	S-curve	Partial rinse	1	$2
Blowoff tube kit	Tube	N/A	1	$5
Midwest Supplies 3-pack	Three-piece	Full	3 + stoppers	$6

Compare the picks

Side by side comparison of every pick
Specification	Three-Piece Twin-Bubble Airlock	S-Type Curved Bubble Airlock	Midwest Supplies 3-Pack Airlocks with Stoppers	Homebrewing Blowoff Tube Kit
Our verdict	Best airlock for most home brewers	Best S-type airlock	Best airlock multipack value	Best blowoff tube for vigorous fermentation
Style	Three-piece (disassembles)	S-type (single curved unit)	Three-piece	Tube with stopper
Stopper size	Fits standard	Fits standard	Not listed	Not listed
Fill liquid	Sanitizer or water	Not listed	Not listed	Not listed
Visibility	Clear plastic, visible bubbles	Clear plastic	Not listed	Not listed
Price	$2	$2	$6	$5
Disassembly	Not listed	No (single piece)	Not listed	Not listed
Quantity	Not listed	Not listed	3 airlocks + 3 stoppers	Not listed
Stoppers included	Not listed	Not listed	Yes (#6 rubber stoppers)	Not listed
For	Not listed	Not listed	Multiple simultaneous fermenters	Not listed
Tube diameter	Not listed	Not listed	Not listed	1 inch
Length	Not listed	Not listed	Not listed	36 inches
Use case	Not listed	Not listed	Not listed	Vigorous primary fermentation
Buy	Check price	Check price	Check price	Check price

Questions people ask

What liquid should I put in my airlock?

Use Star San sanitizer solution diluted at the standard rate (1 oz per 5 gallons of water) in your airlock rather than plain water. Star San does not evaporate as quickly as water during multi-week fermentation, and if fermentation pressure pulls liquid back into the fermenter through the airlock (a suckback event, which can happen when fermentation slows and the fermenter cools), a small amount of Star San solution entering the beer is harmless at diluted concentrations. Plain water that is sucked back into the fermenter adds a small contamination risk if the water is not sanitized. Vodka is sometimes used in airlocks as a pure alternative to sanitizer solution: it is antimicrobial, does not evaporate as quickly as water and is harmless if sucked back into the beer. Avoid filling the airlock beyond the indicated maximum fill line, as overfilling can cause liquid to be forced into the fermenter during active CO2 production.

How do I know if my airlock is working?

A working airlock shows CO2 bubbles passing through the liquid in the airlock during active fermentation. In the first 12 to 48 hours after pitching yeast, CO2 production is visible as regular bubbling through the airlock, with active fermentation producing one bubble every 5 to 30 seconds in a three-piece airlock. If no bubbles appear after 48 hours, first verify the stopper is fully seated and there are no air gaps around the stopper. A loose stopper allows CO2 to escape around the stopper rather than through the airlock, so no bubbles are visible even though fermentation is occurring normally. If the stopper is fully seated and still no bubbles appear after 48 hours, measure the specific gravity with a hydrometer to determine if fermentation has occurred.

How often should I replace my airlock?

Replace airlocks when they crack, when the fill line markings become unreadable or when contamination is suspected. Three-piece airlocks that disassemble fully can last for years with proper cleaning between batches. S-type airlocks with difficult-to-clean interior curves may develop mold residue after extended use in warm fermentation environments; replace them if visible residue that cannot be cleaned remains. At $2 each, airlocks are inexpensive enough to replace annually as a precaution. Keep at least two spare airlocks on hand, as they can crack when a fermenter is moved with the airlock still inserted.

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