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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.

Our customers who use airlock caps often ask us when to change the airlock cap for the storage cap, and when to remove the dunker (weight) from the jar. These are important questions, both because you want the fermentation process to be smooth, but also because you really want to get the airlock lid and the dunker back into use again as soon as possible!

Each Fermenta Lock cap is packaged with a storage cap – so the airlock cap can be switched for the storage cap when the ferment no longer requires venting. Each Fermenta Dunk weight comes with an extender – a plastic disk that is sized for the inside of the jar. Since the weight must be small enough to fit inside the jar opening, it is not large enough to reach the edges. The Extender goes all the way to the edges, and the weight is placed on top of it to hold the food down.

Lacto-fermented foods are LIVING FOODS. This means that the food continues to change and age until it finally spoils. Fermentation delays the point of spoilage by many months – anywhere between 6 and 20 months, depending on the food, the brine strength, the temperature, handling methods, etc. Living foods eventually spoil. This is part of the cycle of health and life. But it also means that during the time when it is healthy and good, it is in a state of constant change. This change is rapid at first, then slower, and finally very slow. The flavors and textures will gradually change over time – not in unpleasant ways, just more or less complex in most cases.

Fermented foods go through three basic stages that are observable. Each change can be responded to by a change in the fermenting process.

First: The initial startup phase. This is where the fermentation process begins. You prepare the food, pack it in salt, or salt brine, add an extender, and then a weight on top of that (several weights for kraut, which requires more weight than brined foods), and then you put the airlock cap on. You can follow this process by SMELL. As the foods inside begin to ferment and release gasses, they will start to vent through the airlock (the orange button on the Fermenta Lock Cap). When that happens, you’ll start to smell a nice pickly smell on the airlock. Once it smells like good pickles (after three to five days – usually three in the summer, five or so in the winter), the fermentation is well established, and you then move the jar to the fridge. If they are left out, especially in the heat, they are more prone to spoilage, though many people leave them out for longer periods before putting them in the fridge (foods were traditionally fermented in a root cellar, or basement, which was typically about 50 degrees, so the change was not required, but this is how we adapt to current conditions). The food can usually be consumed any time after this point, though some people are sensitive to foods that are less than a few weeks old.

Second: The active fermentation phase. After you move the jar to the fridge, the fermentation process continues, it just slows down. If you tip the jar, and bubbles still come up from between the food, it is still in the active phase. LEAVE THE AIRLOCK ON, and leave the dunker in, as long as the food is in the active phase. Once the food is no longer releasing bubbles when you tip the jar, it is entering the storage phase, and at this point, you can switch the airlock cap for a storage cap.

Third: In the storage phase (when it is no longer releasing bubbles), the food will continue to gradually change – fermentation has not stopped, it has just slowed down to an almost imperceptible sequence of changes. One of those changes is that little by little, the food stops floating quite as much. This varies between food types, some will always float some, others will sink more dramatically. Leave one or more weights (and an extender if using one) in the jar as long as the food bounces back up above the level of the brine. If you are using more than one weight, you can usually remove them one at at time over the storage time of the food. Eventually the food stays reasonably covered without the weights or extender. If a bit of the food is above the brine, it is not generally a problem. Foods can be stored for very long periods of time in this third phase, when handled correctly.

We do NOT recommend repacking foods into a smaller jar when amounts decrease!

When you repack, you introduce air through the entire ferment, potentially reducing the overall storage life. Leaving it in the original larger jar means there may be more air above the ferment, but the salt brine limits the movement of the air below the surface of the liquid. From a strictly scientific standpoint, repacking has more potential for harm than leaving it in the larger jar.

When using, remove what you need, using a clean utensil, and try not to stir up the entire jar of food. Wash the extender and dunker with clear water before replacing them if they are still needed.

We have eaten foods handled this way as long as 10 months after placing them in the fridge. Nothing has lasted longer than that – but not because of spoilage. Simply because they are always eaten sooner. The 10 month old food was crisp, tangy, and still had the squeaky feel of a reasonably fresh ferment. There were no signs of spoilage anywhere, even though the weights had long been removed, and the jar was less than half full for months before the last of it was consumed.

Many individuals want a set list of instructions, consisting of exact amounts, precise times, and specific parameters. Fermenting is as much an art as a science, and getting it right has more to do with paying attention to what the food is telling you than it does a list of instructions that have nothing to do with your specific food. There are rules. But the rules are flexible, because the process of pickling is flexible. Learn the rules, and the ferment will tell you what it needs, and when to change the conditions.

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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This website is only equipped to handle orders from US customers (International shipping must be calculated for each order). International Orders are now accepted BY EMAIL from UK, AU, CA, and shipped USPS (other countries will be considered if requested). Please email a list of the items you wish to order, using our Contact page, and we will give you a shipping quote, and then invoice you from PayPal for the total.
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.)