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Fermenting is a science, and a bit of an art. It requires care in a few specific things, but doing it right is not particularly complicated. We provide instructions that are accurate to the best of our knowledge, and which are based on the methods we successfully practice ourselves. There are no guarantees of success or safety with fermented foods. While properly fermented foods are not only safe, but healthy to eat, it is up to you to follow instructions to ensure safety, and to trust your eyes and nose, and don't eat things that do not look or smell like food. We offer no guarantees of success with our product. We do warrant that it is as described, and will do what we say it will, but how you use it is your choice.

A debate rages in some circles regarding open and closed fermenting. For some individuals, an open ferment does not work well for certain items, but it is preferable for a few items in all situations.

An open ferment is one where the surface of the fermenting liquid is exposed to the air – the term is also sometimes used to degenerate fermenting done in anything less than an airlock environment, but that is not correct – closed ferments may be done using standard canning lids (the amount of air that can circulate is negligible – and not significantly more than circulates through an airlock, and both allow gasses to escape if the canning lid is just barely tightened). Open fermenting is the traditional means of fermenting kraut, pickles, wild yeast, and many other pickled or cured items.

A few items, such as milk kefir, or yogurt, generally prefer a closed ferment. This also limits outside contamination with wild yeast or bacteria. Usually that isn’t an issue, and rarely causes a problem in ordinary fermenting situations, even with items that prefer a closed ferment.

For some individuals, open fermenting may result in unpredictable outcomes at times. This has to do with a number of factors, including the temperature, humidity, and with the types of molds and competing bacteria in a given environment (and the irresistible urge some people have to keep opening it). Some homes just have more unfriendly molds and bacterias than others (sometimes due to previous owners, outside influences, or other factors which are not always within the control of the home owner). In our experience, this is the exception, rather than the rule – ferments will work more often than not for most people. But it may be the rule for those individuals who have this particular set of problems – and it may be a serious problem for them.

This is why products such as the Pickle-It system were developed – this system provides a way to release the gasses produced by the fermentation process, but limits the amount of air that can circulate in (it does not prevent air contamination that comes along for the ride in the first place, or that occurs when the container is opened to check – it just limits it during the wait times). It does not create an anaerobic environment, in spite of claims that it does – it just limits the amount of outside contamination potential when the jar is not open. An airlock only prevents air movement when air pressures are equal. If air pressures inside are greater, gasses bubble through the airlock. If air pressures outside are greater, gasses will bubble in through the airlock the same way they bubble out. This is true of any lidded jar as well, and the difference in contamination potential between an airlock system, and a lidded jar that is not opened frequently, is very small. The biggest difference is gas release – an airlock prevents messy encounters with gas producing bacteria.

The success of airlock jar systems, as reported by users, is partly due to method, not exclusively the system. People admit to fermenting more with their new jars – this means they finally care enough to work out the bugs in their method (when you have an expensive system you feel obligated to use it also). The jars also encourage a person to NOT open and mess with it – which alone is a large enough factor to make a huge difference in success rates. I can discipline myself to leave the jar alone well enough to save the hundreds of dollars it would cost me to acquire enough airlock jars to replace my perfectly functional collection of buckets, jars, bottles, crocks, and zip bags.

Claims regarding healing rates involving foods fermented in airlock systems as opposed to using airlock systems also can be logically explained for the same reasons. Method affects outcome, regardless of the system, and if you ferment more, and use more fermented foods, you may overcome a problem you were not able to at other times. My own health gains are sufficient for my own satisfaction – I was gluten intolerant, lactose intolerant, pre-diabetic, had heart arythmias, had progressive painful arthritis, daily headaches, and auto-immune Crohn’s Disease, and had so many food intolerances that I could barely eat. I had so many sensitivities to chemicals that I could not use most shampoos, deodorants, laundry detergents, soaps, or other personal care items. Those things are gone. My blood sugar is balanced, I eat dairy, wheat, eggs, pork, tuna, and other foods that made me sick for years. I rarely have headaches, I barely have arthritis, the auto-immune disease is gone, and my bowel is mostly healed – I have a few sensitivities to chemicals remaining that give me problems now and again, which are lessening all the time. I did not just learn how to LIVE with a condition, I have REVERSED it. I honestly don’t think I can take credit for that – in the end, it was truly a miracle from God which enabled me to heal. But I know what worked for me to do my part, and I know what works now to KEEP the blessing.

For most situations, open ferments work perfectly well, and can result in a wider variety of healthy microbes. An open ferment is the only way to do some things (they can help with some wild yeast cultures). Open ferments are also preferable when fermenting non-alcoholic fruit based foods. An open ferment builds up alcohol to a higher initial concentration than a closed ferment, but it eliminates the alcohol better if the ferment is allowed to complete – leaving it open to the air encourages the microbes which create a vinegary result rather than an alcoholic result. That won’t happen in a closed ferment – it does build up a little less alcohol initially, but it retains the alcohol instead of converting it to acid (vinegar cannot be produced in a closed fermenting environment, you get hard cider instead), resulting in a far higher alcohol content in the finished ferment.

Contrary to popular myth, airlocks are NOT the “historical” way of fermenting ANYTHING, including alcoholic beverages. Mankind has been fermenting foods for more than 9000 years, according to archeological evidence, and water locks have only been used for a couple hundred of those years. They are a rather new invention on the scene. Indeed, some breweries still ferment beverages in open vats. After the initial fermentation period, they are closed up to retain the alcohol and allow long term aging (slower secondary fermentation which builds up less gas).

Some of the “evidence” regarding open versus closed ferments is misleading, biased, and based on deliberate omission of parts of the process. This is true of a lot of information regarding “testing” of fermented foods. It is often done in a home kitchen, without proper controls, and frequently without a full understanding of the principles involved. Results are often based on incomplete fermentation results (for example, comparing open and closed fermentation alcohol levels at 3 and 5 days, but not at 30 days when the process is fully completed for the open ferment). Results are also often given only for one side of the equation – for example, statements of mold spores found in kefir which was incubated in a mason jar, without corresponding mold spore results from kefir incubated in an airlock system.

Statistics are often quoted, pointing out a failing in one method, while leaving out that the same flaw applies to the other method (they just hope you won’t notice). They often focus on a minor factor, while ignoring the major factors that present larger problems (such as focusing on air circulation during storage time, rather than on disruption air exposures when containers are opened which are a larger problem). They also frequently fail to observe time tested patterns that have proven accurate for millenia (such as airlock fermentation for alcoholic beverages, and open fermentation for non-alcoholic pickled foods). Many focus entirely on lactic acid baccillus, while completely ignoring all other healthy bacteria and yeasts (and lactic acid baccillus is only part of the picture, not the whole thing). And one often referenced kitchen test for alcohol content in fermented soda involved heating the soda prior to testing the alcohol content, thereby completely invalidating the test results! (Alcohol evaporates quickly when heated, or even if stirred very much.)

The “science” is often twisted to suit the goal of the presenter. So be suspicious, apply common sense and logic, and if someone claims that their method is traditional or historic, ask them who, and when, and how. If they present “evidence” look at the entire picture, not just the little piece they want you to see. Always look to see if the “fault” they are pointing at in their competition is not present in them also (often it is, they just don’t mention it!).

This is NOT a debate here, merely an attempt to accurately outline the pros and cons of the different methods, so you can choose wisely for the kinds of things you wish to do. Open ferments are best for some things, closed ferments for others, and some people prefer an airlock for closed ferments. A wide range of ferments may be done either way.

Keeping food under the brine for brine pickling is far more important than the kind of container you ferment the pickles within. Sellers of water lock systems always tell you that you MUST keep the food under the brine – if their method were truly what they claim it to be, it would not matter. It is keeping the food under the brine, now, and historically, that properly pickles salt brined foods.

Success depends more on whether you follow proper fermenting procedures than it does on whether or not you use an airlock system. Disturb it as little as possible, make sure foods stay under the brine, remove scum on top of brines prior to removing any food, and make sure food is back under the brine after removing any portion. Ferments must be allowed to complete to the point where pickling has occurred, and then transferred to a lidded jar that is essentially airtight, and placed in the refrigerator.

(There is an entirely different argument about what is, and is not, airtight, but even an airlock or water lock system is not absolutely airtight, air still moves through the water at a slow rate – and it moves through fresh water faster than it does through salt water. A rubber plug replacing the airlock is not entirely airtight either. The goal is not absolute – it is to restrict to the point where the amount that circulates is insignificant, and any rubber gasket lid will accomplish that goal. Beer making requirements are irrelevant – beer builds up tremendous pressure in the bottle, making the requirements different than the requirements for storing pickled foods in the fridge. A rubber gasket seal is perfectly adequate, and won’t allow any degree of significant air transferrance. Kerr and Ball [now the same company] would not warrant their gaskets as airtight for legal reasons, but air WON’T move past a rubber seal of any thickness unless the glass is damaged, as in a chip out of the top edge of the jar, or if the outside and inside pressures are very unequal, in which case, a rubber stopper is just as likely to fail, possibly explosively.)

I have seen it recommended that fermented foods be transferred to a smaller container when a significant portion is used, but I think you’ll lose as much as you gain from that, especially if it is a short storage item, and not one you are using for a period of several months. The reason is that transferring it from one container to another means massive air exposure throughout the entire contents, while leaving it in the original jar means only the top surfaces are exposed very much. Remember, the majority of air exposure comes from handling, not from storage method.

Some sources claim that foods stored in an airlock system (they did not specify whether they replaced the airlock with a rubber stopper) will stay fresh longer in the fridge. This may be true, I honestly do not know. Nothing I make lasts long enough to develop a problem! I only ferment foods that we love to eat. No point in fermenting things that we want to store for years, drying is more stable and does not require fridge or root cellar space. And foods that are frequently opened and used from will perform equally well between a specialized system and a lidded canning jar, simply the only air exposure that matters is exposure caused by opening the jar when foods are being removed.

The things I have had that failed did so because I dropped the ball – most commonly, my wild yeast develops mold because I forget to feed it. This is true of most situations where fermenting fails – there is some little error in the method that is hindering success, such as excessive handling, fermenting it near something that interferes (like a bunch of ripening bananas), or getting confused about when it needs a lid and when it does not.

Fermented foods are “living foods”. They change through the course of storage. They HAVE to. If they do not, they are no longer living. They are dead and embalmed. So longer storage is not necessarily a plus – I can make any kind of fermented food store indefinitely by pasteurizing and sealing it. But doing so kills the living microbes that I want. Properly fermented foods store for an average of 4-12 months, depending upon how they are stored (heat is a major factor in storage life – warmth speeds up the life cycle and hastens the end of usefulness as food). Since I tend to ferment things in small batches, of at most, a few jars at a time, it is used up long before that time anyway! Even if I wanted something to last longer, I would not choose an airlock system as a means of storing it longer. At $25 apiece and more, they are simply not affordable as long term storage containers! A canning jar, packed close to the top, with sufficient moisture to keep the food pieces under liquid, with a lid screwed on snug, will yield good results if left alone in a cool and dark place.

A friend of mine uses the Pickle-It system and swears by it. She loves it and feels she cannot successfully ferment many types of foods in her particular situation without it. She ferments different types of foods than what we do, and does not do types that require an open ferment. Fermenta Lock accomplishes the same thing.

We use many open ferments, using Fermenta Caps, and some closed ferments using Fermenta Lock, and enjoy equivalent success. We had the same kind of success using regular canning lids (loosening the cap enough to hiss, tightening it back down when the hissing stops) to keep them from building up dangerous levels of pressure – it was just less convenient. Using canning lids which do not vent themselves requires more vigilance on our part to avoid messy encounters. Fermenta Lock is simpler because we put it on and walk away. I can, and have, done it all three ways, and still do, simply because not all closed ferments need an airlock cap.

However you choose to ferment your foods, we wish you success.

The ORIGINAL one-way valve fermenting airlock! Imitation IS the sincerest form of flattery, and we have noticed that our product has been copied by other sellers of fermenting products. Remember, if you see someone else selling a one-way valve airlock for fermenting, THEY copied US, not the other way around! Fermenta Lock is still the only original invention, handmade in the US. If it isn't orange, it isn't the original!

We invented Fermenta Lock, Fermenta Free, and the valve used for Fermenta Fido and other Fermenta Airlock products. We invented Fermenta Dunk Extender. Patents are prohibitively expensive, and designed by the government not to protect the rights of individuals, but to provide another source of revenue and control for the government and lawyers. We are good at what we do. We have endless ideas and endless creativity, and competition does not scare us. Impatient thieves do not scare us - they are too busy taking shortcuts to make a success of it anyway, and they won't want to take the effort to actually MAKE a product and fill orders.

So if you want to copy our idea, go right ahead. If you want to market and sell a competing product, you are welcome to do so, as long as you do not patent our idea - we had it first, and our posts on FaceBook announcing the invention and launch of it will prove that. This idea is officially in the public domain, placed there by us. We will NOT release supply sources, or part names unless you want to buy them - we'll be happy to sell you an instruction kit. If you buy our product, or look at the images and figure it out for yourself, good on you. Compete with us if you like, just don't screw us, and we'll get along just fine. Big companies who might want to screw us may have more money, and more lawyers than we do, but we have more to gain by suing the pants off a big company, and believe me, we will be well motivated to do so if anyone patents our idea and claims it as their own - this is a free idea. Everybody now owns it.

Published June 23, 2012

Wholesale, Export, and Manufacture of this product by other companies is an option. International distributorships are available for those wishing to export. Please email us to inquire about access to our wholesale website, or in regards to manufacturing any of our products.

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Uses of Fermenta Lock

Fermenta Lock is a compact airlock cap for mason jars, to help in making old fashioned brined pickles, and other lacto-fermented foods. Use Fermenta Lock for:

Pickles (all kinds)
Sauer Kraut
Milk Kefir
Bean Paste/Hummus
Sourdough Starter (if started with culture or yeast)
Anything which needs gas release without a lot of air circulation.

Customer Comments

“Living down in Guatemala, we have quite a lot of dampness in our houses and mold is an ongoing battle. After a long dose of antibiotics due to a parasite, I absolutely required probiotics to get my gut back in order and I know homemade sauerkraut has more probiotic content than anything else I could find here. I wasn’t able to make my beloved sauerkraut or even Kombucha in my kitchen because mold would start growing immediately on the top. Your Fermenta Locks have literally been a lifesaver for me! No more mold, and PERFECT Kraut EVERY time!!! Thank you for creating such a wonderful product!!!”

A. Kratzert

“Oh how I wish I had found you first!! Too many experts and too many bucks later I discovered your “Lock” and the sheer elegance and simplicity of your system.Thank you for your help and affordability, it makes healthy food attainable.”


“I came back to order more FermentaCaps. A wonderful innovation. I have not lost a single batch of sauerkraut since I started using the original Fermenta Locks.”


“Please continue your good work on producing such a great product. I’ve tried lots of other kinds of airlocks- the 3 piece water lock, pickle pipes, fermilid, boss pickler, and I think yours is the best design and quality. I’d like to order another 100 of them right now, but I’ll have to wait a bit. I’ve had lifelong health challenges. I’m 38 and about 20 years ago my health was so bad I didn’t feel like living most of the time. Now my health is the best it’s ever been and it wouldn’t be possible without fermented vegetables, they have made a huge improvement in my health.”


(Last names omitted to protect customer privacy.)