Small batch fermentation in glass canning jars (Mason jars) has come a long way in the past few years during which a wide selection of fermentation lids have been introduced to the market.
Lucky for us. However…
So many choices can be overwhelming.
Don’t worry. I’ve selected the best fermentation lids with an airlock for the home fermenter, will share pros and cons, have included some insider observations and answer a few burning questions:
Do you need a fermentation weight when fermenting in a jar with an airlock?
Do you even need an airlock?
A quick overview of how airlocks work.
- How Does An Airlock Work?
- Do You Still Need a Fermentation Weight when Fermenting in a Jar with an Airlock?
- Do I Need An Airlock?
- How Do I Select a Fermentation Lid Airlock Setup?
- Fermentation Lids with Three-Piece Water-Filled Cup Airlocks
- Fermentation Lids with One-Way Waterless Airlock Valves
- Water-Sealed Airlock Lid
- Fermentation Lids (Storage Caps) Without An Airlock
- DIY Fermentation Lids
How Does An Airlock Work?
An airlock is attached to, or built into, your jar lid and is used to create an anaerobic (without air) fermentation environment with a glass canning jar. Shown in the picture above are three different styles of airlocks.
- Three-Piece Water-Filled Cup Airlocks
- One-Way Waterless Self-Sealing Airlock Valves
- Water-Sealed Fermentation Lids
An airlock is a one-way valve that allows gases (hydrogen, methane and carbon dioxide) created during fermentation to escape while preventing oxygen, bacteria, mold spores or wild yeasts from the atmosphere from entering your jar and causing your ferment to mold or spoil.
There are various ways in which these valves work. You may be most familiar with the plastic three-piece water-filled cup airlock commonly used by wine and beer makers. This style of airlock (shown on the first jar), along with the newer low-profile waterless airlocks (shown on the second jar) and even water-sealed fermentation lids (shown on the last two jars), are discussed in greater detail below.
There is a bit of controversy out there on whether or not you can establish an anaerobic environment with a glass canning jar. Opponents feel that the sealing compound in the jar lid just isn’t thick enough nor the ring strong enough to create a reliable, completely airtight seal and that an airtight seal is only possible with a bail-top clamp-down lid as shown below (or a water-sealed fermentation crock).
The theory is that only Fido-style fermentation jars, sold under the Pickle-it and The Probiotic Jar(tm) Lid Kit and Quick Start Guide to Old World Traditional Pickling and Anaerobic Fermentation names, with a bail-top clamp-down lid are truly anaerobic. Further, they feel that with mason jars you will often end up with mold and that you are not able to produce the same levels of beneficial bacteria during fermentation as you can with a Fido-style jar. My experience has taught me otherwise.
Not only do I find the $40 startup costs for a single Fido-style jar fermentation set up steep, the lids awkward and the jars bulky but, I have successfully fermented – in glass canning jars – hundreds of batches of delicious sauerkraut. It would take a series of lab tests on the bacteria levels in various fermentation setups to persuade me to stop fermenting in canning jars, with or without airlocks.
Controversy aside, if you already have Fido-style jars, by all means, use them. They are great jars and are sure to form an anaerobic seal. If not, purchase what works for you and get fermenting.
For a long-term approach, I recommend starting with glass canning jars – with or without the startup costs of airlocks – to gain experience and develop intuition and then purchasing a water-sealed fermentation crock where I feel the best quality of fermentation happens.
Advantages and disadvantages of using an airlock on your jar, no matter the style of the jar are as follows.
Advantages to Using an Airlock on your Fermentation Jar
- Prevent air from entering your jar.
- Prevent mold spores and yeasts from entering your jar.
- No need to burp your jar.
- No daily maintenance.
- No exploding jars if you forget to burp them, or forget to leave the lid loose.
- Less odor.
Disadvantages to Using an Airlock on your Fermentation Jar
- An unexpected overflow of brine into a three-piece water-filled airlock can be messy to clean.
- Brine overflow may remain and then dry inside a waterless airlock valve causing it to seal and not let gases escape.
- Water levels in some styles of airlocks need to be monitored on a regular basis.
- There are extra pieces to keep track of when using the 3-piece water-filled airlock.
- An added expense.
You won’t be using these airlock lids when storing your sauerkraut, so you just need enough for the number of jars you may be fermenting at any one time.
Do You Still Need a Fermentation Weight when Fermenting in a Jar with an Airlock?
Let me explain why.
Even when using an airlock, you will need a fermentation weight when fermenting sauerkraut so that you can hold your packed mixture below the brine. A weight is not always necessary with brine-pickled vegetables – like Fermented Carrots – that tend to stay below the brine without a weight. This is because your packed sauerkraut can work its way up and out of the brine.
By the power of our Mighty Microbes!
During the first stage of fermentation – typically, the first 5-7 days – CO2 gases are created by bacteria present in your ferment.
These air bubbles get trapped in a tightly packed mixture – like sauerkraut – and cause the mixture to expand and move up and out of the brine. A weight works to hold the expanding ferment under the brine and force the air bubbles to work their way up and out the of mixture where they rise to the surface of the brine and then exit the jar through an airlock.
Some fermentation weights work better than others. I am now making a distinction between a fermentation weight and a fermentation gate – a term I have necessarily coined as I have witnessed how these CO2 gases can wreak havoc in your jar.
A fermentation weight sits on top of your ferment and by its sheer weight is intended to hold your ferment below the brine. A Pickle Pebble is an example of this and generally works unless you have an especially active ferment in which you may have to press down on the weight to help trapped air bubbles rise to the surface and your packed mixture to contract back down and under the brine.
A jar filled with water also works as a weight though in this example you still have the surface of your brine exposed to air.
A fermentation gate is “locked” in the neck of your jar (or placed on top of your ferment where it is locked in place with your lid) and does not move no matter how hard the Mighty Microbes push up against the gate (or how much the mixture expands).
The Pickle Pusher (first jar), Canning Buddies (middle jar) and the small jar (last picture) that I recommend using in my teaching recipe – How to Make Sauerkraut in a Jar in 7 Simple Steps [Healthy, Flavorful, Easy] – are all examples of fermentation gates. The following two reviews show how well the Pickle Pusher and the Canning Buddies perform in various ferments.
So, yes you still need a fermentation weight when fermenting in a jar with or without an airlock.
Do I Need An Airlock?
No, you do not have to use an airlock. You can successfully ferment many a batch of sauerkraut without one.
Do you get better results with an airlock?
Most likely yes, but I don’t have lab tests to back that up. I find it more important to use the right amount of salt and then:
1) find a way to reduce air exposure and…
2) allow CO2 gasses to escape.
To reduce air exposure, select a way to hold your ferment below the brine and put a lid on it.
To allow CO2 gases to escape, you can use an airlock, or…
you can use a regular jar lid, but screw it on a tad loose. Since the lid is loose, air can flow in and out of your jar, though not enough to ruin your ferment. This is not a true anaerobic setup, but seems to work just fine and is how I have fermented hundreds of batches of delicious sauerkraut and is what I recommend in my teaching recipe.
Lids without airlocks can be used both for fermentation and for storage and offer a low-cost entry into small-jar fermentation. Until 2016, I always sealed my jar of fermenting sauerkraut with a white plastic one-piece storage cap. No airlock. No rubber seal.
Since 2016, due not only with the proliferation of fermentation gadgets flooding the market but also the need to determine which airlocks work best for my readers, I have been using a variety of airlocks when fermenting.
However, I still recommend a simple loose-lid setup for the first few jars of sauerkraut you ferment as a low-cost entry for testing the world of fermentation. With a bit of experience under your belt and knowing if fermentation is something you want to pursue, you will then be able to choose what gadget(s) you want to purchase – or not.
How Do I Select a Fermentation Lid Airlock Setup?
We each have our own personal style and needs to take into consideration when making a purchase. Some ticklers for you:
- What materials are you comfortable with using in your ferment. No plastic whatsoever? Are you OK with silicone? Or, do you want to use only glass? Stainless steel?
- How many airlock lids will you have in use at any one time? Will you ferment a few jars periodically throughout the year or all within a few weeks with freshly harvested cabbage?
- How much money are you willing to invest? Do you want to save some of that money for a water-sealed fermentation crock?
- Is some of that money better spent on a scale? Or a slicer to up the quality of your sauerkraut?
- Are you looking for a low-profile design – waterless airlocks – or are you OK with the 3-piece airlocks?
- Do you care where the fermentation lid and airlock setup is made? Be willing to shell out some extra $$$ for products made in the USA. Sadly.
Keep your answers in mind as you learn about the various styles of airlocks.
Fermentation Lids with Three-Piece Water-Filled Cup Airlocks
You may be most familiar with the three-piece water-filled cup airlocks used by the wine and beer industries and now adapted for use by the vegetable fermentation world. They are quite effective, somewhat inexpensive – especially if you put together your own lid from items purchased at a local wine & beer fermentation supply store – and readily available.
The airlock cup is inserted into a hole drilled in your lid that has been outfitted with a silicone or rubber grommet. The airlock is partially filled with water, an inner cap placed over the tube inside and then a secondary cap popped on. Gases work their way out of your ferment, up the pipe and into the water in the airlock.
From there, air bubbles rise to the surface and escape through the pinholes in the lid. No air can enter the jar. Gases can escape.
There are numerous kits available. The ones I’ve listed have features I like and are at a decent price point. I have not purchased or tested any of these kits but they have been popular choices for my readers.
The most common complaint of the 3-piece water-filled airlock are all the bits and pieces to keep clean and keep track of. In addition, they have a much higher profile than the waterless airlock valves discussed in the next section.
Popular Three-Piece Water-Filled Cup Airlocks
1. Sauer System Mason Jar Fermentation Airlock Lid Kit by Fementology
What I like about this setup by Fermentology is the quality of the lid used. It is thick. It is durable. It won’t easily crack. And, it has angled sides to make it easier to grip when trying to remove a tight lid. This kit is frequently ordered by my readers.
In addition, the underside of each lid has a custom gasket channel which holds the BPA-free silicone gasket in place at all times and allows the lid to screw down all the way into place and not sit high on your jar, a complaint of mine with aftermarket gaskets. And, if you look real close, you can see that a section of the channel wall for the gasket is cut out. This makes for very easy removal of the gasket. 🙂
- Weights – Sauer Stones – sold separately or sometimes available in a kit.
- Plastic lid is the Tough Top from MasonTops. It is thicker and more durable than most plastic lids. The underside of each lid has a custom gasket channel which holds the BPA-free silicone gasket in place at all times. In addition, the angled sides on the lid make it easier to grip when trying to remove a tight lid.
- All components are certified BPA-Free and dishwasher safe.
- Includes seal plugs that are put in place – after removing the airlock – when fermentation is done.
- Made in China.
2. Fermentation Kit by Quality Reliable Products
What I like about this kit by Quality Reliable Products is the design of their “food retainer aeration cup.” It sits in the mouth of the jar, where it stays in place and keeps your expanding, fermenting sauerkraut submerged underneath the brine. Especially nice are the slits in the side of the cup to allow the brine to expand into it as necessary and not overflow your jar.
- White plastic lid, silicone gasket, silicone grommet, 3-piece airlock, storage plug, “food retainer cup” that is placed on top of your ferment to hold it below the brine; acts as your “weight” and works like the little jar I call for in my teaching recipe, except that it has slits cut in it to allow for brine expansion.
- Fermentation “weights” included. According to reviews, these little plastic cups are prone to breaking so handle carefully.
- No instructions included in the shipment.
- ALL QRP® parts and products are BPA-free USDA Food Grade Compliant and are produced by a reputable food container manufacturer.
- Made in China.
Fermentation Lids with One-Way Waterless Airlock Valves
For a one-way waterless airlock, a small, low-profile valve is inserted or built into your fermentation lid. They come in a variety of styles and are generally made from silicone. One style of these self-sealing valves is a small, cross-hair cut in the silicone that only opens when there is enough pressure in the jar to force it open. Outside pressure closes the seal. This one-way valve lets carbon dioxide escape from your jar, but does not allow air from the outside to enter back into the jar.
Some use a simple silicone umbrella valve that lifts up to let gases escape when the pressure inside your jar is great enough and remains seated on the lid when not. Oxygen, bacteria and airborne yeasts can’t get into your jar; gases escape as necessary.
What follows are some of the currently available fermentation lids with one-way waterless airlock valves. Though often sold in a set, they range in price from $4.50 to $11.66 for a single setup for a wide-mouth mason jar.
One-way waterless airlock valves are fairly new to the fermentation market. I like their low profile. ease of use and that there of so few parts to keep track of or clean.
Popular One-Way Waterless Airlock Valves
3. Pickle Pipe by MasonTops
The Pickle Pipe is a silicone disc with a nipple-like bump centered on the top.
The nipple has a small cross-hair cut in it that works as a one-way valve to let the carbon dioxide escape from your jar, but not allow air from the outside to enter back into the jar
- Set includes 4 silicone Pickle Pipes (red, teal, purple, blue).
- Bpa-free, food-grade silicone is dishwasher safe and reusable for many years.
- Superior in quality to copycats of this product.
- Made in China.
The Pickle Pipes have become my go-to waterless airlock. They easily and quickly attach to your jar. The best part? The visual feedback during fermentation.
See the slight bulge in the lid of my jar of Fermented Carrots?
That tells me the Mighty Microbes are hard at work. The gases they make are building up and will soon create enough pressure to open the cross-hair cut in the nipple. A comforting visual in case you missed seeing the air bubbles.
The lid will move up (looking concave) and down (looking flat or convex) with temperature swings and changes in barometric pressure.
Your own weather station!
A full review of Mason Tops Pickle Pebbles and Pickle Pipes HERE.Pickle Pipes by Mason Tops
4. FermentEm Kit by FermentEm
The one-way valve in the FermentEm Kit by FermentEm is hidden inside a two-inch tall airlock about the diameter of a pencil. This airlock is inserted into a white, plastic lid – with silicone grommet. Any built-up gases make their way out the airlock; no air can enter your fermentation jar.
Kit includes a plug for each lid. When fermentation is done, the airlock is removed and the plug put in place. You could also just save the lids for fermentation and instead replace the lid with a storage cap, a white plastic lid without the hole/grommet setup.
- The arrow imprinted on the center ring of the airlock – hard to see – MUST BE POINTED UP in order for the gases to move up and out of your jar.
- Some users complain that the silicone gasket that is placed inside your lid easily falls out when trying to screw the lid onto the jar. Detailed instructions on their website explain how to successfully put the lid on your jar.
- Excellent customer support.
- All components – except the white caps – are made in the USA.
I love the simplicity of these airlocks. You do have to make sure they are inserted in the right direction. I would prefer using them in a lid with either a built-in gasket or a lid that has a recessed groove for the gasket. I will probably transfer these valves to iLids, an option discussed in the DIY Airlock Lids section below.FermentEm Kit by FermentEm
5. Stainless Steel Fermentation Jar Lid Kit by Trellis + Co.
The airlock in the Trellis + Co. stainless steel fermentation lid is a simple silicone umbrella valve that lifts up to let gases escape when the pressure inside your jar is great enough and remains seated on the lid when not.
Trellis & Co.’s design philosophy:
“The KISS Principle. Ever heard of that? It stands for KEEP IT SIMPLE, STUPID. That’s what we did with our fermenting lids.
Here’s how it works: Normally the valve remains sealed against the lid surface. This prevents oxygen and bacteria from entering the jar. As carbon dioxide builds up as a result of the fermentation process, the valve flexes up and releases the pressure only as necessary.”
- No plastics.
- 316 Stainless Steel, the most corrosive-resistant metal commercially available and the small metal used in implantable medical devices and pharmaceutical ferments. Lid will not corrode or leach anything into your ferments.
- Lid designed with a recess for a silicone gasket to properly fit and ensure that lid screws onto jar completely.
- You can tell that a lot of work was involved in the engineering of the stainless steel lid. It fits snugly and doesn’t sit high on your jar, a common issue with gaskets added aftermarket to existing lids. The silicone gaskets are cut differently – to snugly fit in the lid – than others on the market.
- Made in Utah, United States.
Beautiful lids! I use my set frequently and like the feel and quality of the stainless steel lid. Once I have screwed the lid in place, I do make sure the umbrella valve is properly seated.Trellis + Co. Stainless Steel Fermentation Kit
6. Easy Fermenter by Nourished Essentials
A low-profile waterless airlock valve is built into a silicone section in the center of the EasyFermenter lid. Gases escape; oxygen can’t enter your jar.
One nice bonus about the EasyFermenter lid is that it has an integrated easy release tab. A common struggle with lids that form a tight, anaerobic seal is that they are pulled so snugly onto your jar due to the vacuum created. This – along with any brine that may dry in the jar rim – makes it very difficult to remove fermentation lids.
Other manufacturers have added ridges or texture to the lid rim that tend not to work whereas the tab allows you to get apply enough force to loosen the lid.
- Kit includes 3 lids and oxygen extractor pump (to suck out the oxygen during the later stages of your ferments).
- Date Tracker on the lid can be used to indicate the date you started fermenting.
- All Components BPA Free and Food Safe.
- Great customer support. Free membership to their Fermenting Club
- Made in China.
I bought myself this kit last summer and have more than once appreciated that handy tab on the lid. It makes it so much easier to remove a stuck lid. In addition, the lid has a nice recessed grove for the silicone sealing gasket.
The Date Tracker on some of my lids is a bit loose and can move unintentionally if the jar is tilted.
I haven’t made much use of the oxygen extractor pump since I don’t want to use a $12.00 lid to store my dozens of jars of ferments. It would be handy however during the last few weeks of fermentation to “seal” a jar after opening to taste your ferment.Easy Fermenter by Nourished Essentials
For readers in the United Kingdom, worth a quick mention is the SteriLock. It is a waterless airlock similar to the FermentEm plastic pipe but can be outfitted with a carbon filter to trap and absorb odors. Available only in the UK through Amazon.co.uk or the company website.
Water-Sealed Airlock Lid
Water-sealed fermentation lids work in the same manner as a water-sealed fermentation crock. There is a moat built into your lid that you fill with water and then set a cap or lid is placed down into the moat.
Gases make their way up and out of your ferment and then bubble up and out through the water in the moat. Oxygen, mold spores and wild yeast can’t work their way into the jar. Your jar is sealed by the use of water.
What follows are the two currently available fermentation lids with a water-sealed airlock lid. Each of these sets includes a weight.
Popular Water-sealed Airlock Lids
8. Fermentation Lid by Kraut Source
The Kraut Source Fermentation Lid is a series of stainless steel parts: Plate, Spring, Moat, Gasket and Cap. Once assembled and placed on your jar, the Spring is released allowing it to push down onto the jars’ contents to keep them submerged.
- Kit includes Plate, Spring, Moat, Gasket, and Cap along with an extra gasket.
- Made of Stainless Steel and FDA Food Grade Silicone.
- Includes instruction booklet and link to downloadable recipes.
- Made in China.
I especially like how the spring-activated plate adjusts to the height of the ingredients in your jar. In this image, my Raisin Chutney safely fermented below the brine, a challenging task with a paste ferment when there is not a lot of brine.
You do have to remember to keep an eye on the water level in the trough especially when fermenting for more than a week or two.Fermentation Lid by Kraut Source
9. Home Fermentation Kit by Ferment’n
The Ferment’n Home Fermentation Kit contains is a two piece plastic lid and a ceramic weight.
The bottom part of the lid slides down into the opening of a wide-mouth mason jar and is secured with a metal canning band. Water is poured into the moat in the lid. The top part of the lid – a cap with two prongs – is placed on top.
- Kit includes 2-piece lid and weight. You’ll need to use your own metal canning band to secure the lid.
- Weight is approximately 5 ounces.
- BPA free plastic, ceramic weight. Dishwasher safe.
- Made in the USA.
What I like about the Ferment'n fermentation lid is that the moat is sealed such that water does not evaporate and cause the jar to lose its seal. A few weeks into fermentation, a quick visual check of the moat showed plenty of water. In addition, if you fill your jar too full, or if you have an especially active ferment, the moat acts as a spot for overflowing brine to accumulate. Less chance of brine spilling onto your countertop.
A few weeks into fermentation, a quick visual check of the moat showed plenty of water. In addition, if you fill your jar too full, or if you have an especially active ferment, the moat acts as a spot for overflowing brine to flow in and out of. Less chance of brine spilling onto your countertop.Home Fermentation Kit by Ferment'n
Fermentation Lids (Storage Caps) Without An Airlock
Fermentation can happen in a glass canning jar using the lid that came with your canning jars or with another lid selected from the following list. I stopped using the metal can lid and rim because I found the mixed metals would rust with the acid in my ferments. In addition, I prefer the clean simplicity of a one-piece lid.
Just be sure to leave the lid a tad loose during the active stage of fermentation, usually the first 7 days.
NOTE: Make sure to order the right size! Wide-mouth, most likely.
White Plastic Storage Cap by Ball
Ball White Plastic Storage Cap.
$6.28 – Set of 8. $0.79 each.
BPA free. Made in China.
I use these caps both for fermentation and for storing my ferments. After market silicone gaskets are available but, since there is no recessed grove in the lid, the lid will sit high on your jar.
iLIDS Wide-Mouth Mason Jar Storage Lids by Intelligent Lids
iLids Wide-Mouth Mason Jar Storage Lids.
$21.35 – Set of 3. $7.32 each.
Made from recyclable material (BPA and phthalate-free) and dishwasher safe. Made in the USA.
These lids have become my favorites and would be my number one choice to use when making my own fermentation lid.
Tough Tops Plastic Wide-Mouth Mason Jar Storage Lids by MasonTops
Tough Tops Plastic Wide-Mouth Storage Lids.
$14.95 – Set of 4. $3.74 each.
Made from sturdy food-safe and BPA free materials and includes silicone gasket seals to create a secure airtight seal. Made in China.
Sturdy white plastic with ridges and groove cut into lid. With their price point – and the way the lid is cut – these lids might make a move into my top spot.
DIY Fermentation Lids
Would you like to make a few of your own fermentation lids?
If you have access to a local beer and wine making supply store, you can make a few inexpensive fermentation lids with just a few parts. Some of the fermentation lids just require putting together a few pieces, some require the use of a drill and one extra equipment and lots of patience.
DIY Fermentation Lids with reCAP Jar Lid
One company sells these airlocks in a kit but they are rather expensive.
A quick trip to town, a few dollars spent and I had my fermentation setup. You pop open the cap on the lid, insert the bung and then insert your airlock into the hole in the bung.
DIY Fermentation Lids with Your Choice of Jar Lid
You could use the Ball White Plastic Storage Caps for your lid, but I would recommend that you select a lid with a built-it gasket (or groove in the lid for the gasket to seat down into) for the best seal. I would stay away from the metal canning lids. They tend to rust due to the acidic nature of your ferments.
You will have to pay close attention to grommet size and lid thickness when purchasing grommets and drilling your hole.
DIY Airlock: Fruit and Veggie Ferments by Wardee at Traditional Cooking School has a few tips to get you started on making your own fermentation lids.
This video shows a fermentation lid being made with the TATTLER canning jar lid that there is some concern about the safety of the components in their plastic.
Fermentation Lids for Fermenting at Home in Mason Jars
There you have it. Now you know whether or not you need a weight when fermenting in a Mason jar, if you really need an airlock and which fermentation lids will work for you.
What is your favorite fermentation lid? Please share in the comments. Then pick a recipe and MakeSauerkraut!
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Last update on 2019-04-18 / Affiliate links / Images from Amazon Product Advertising API