How to Use Airlock for Fermenting Vegetables and Why

Fermentation isn’t a new technique when it comes to food preservation. Evidence indicates that early civilizations, such as the ancient Romans and various Asian cultures, fermented food for thousands of years. Be it beer or bread, cheese or wine, around the world the process of fermenting is as old as time. To learn how to use an airlock for fermenting vegetables, and why, keep reading.

Fermenting vegetables is an ancient art found in many cultures from Korean kimchi and Indian chutneys to the widespread consumption of sauerkraut across Europe. The basis of all these foods is the Lacto-fermentation process where salt inhibits the growth of bad bacteria while allowing the good bacteria to break down the sugars in the food and preserve it.

Why Use an Airlock for Fermenting Vegetables

Your Anaerobic Environment

So if this process has been around so long, why all of a sudden are people now using an airlock for fermenting vegetables? That answer can be summed up in one word, safety! Since the Lacto-fermentation process should take place in an anaerobic (without air) environment, it is key to food safety.

As the fermentation process occurs, it gives off carbon dioxide and lactic acid. Since carbon dioxide is heavier than air, the airlock allows the air to be pushed out of your fermenting vessel safely without allowing more air in, thus creating an anaerobic environment in your fermenting vessel.

Alternative Method

But can’t I just put a lid on a canning jar? While you can, it requires you to “burp,” or let the air out of your vessel often, thus allowing more air, and non-desirable bacteria, back in the jar. If you don’t release the pressure created by the production of carbon dioxide you run the risk of your vessel exploding and no one wants that! Airlocks take the guesswork out of when to “burp” and aid in providing the proper anaerobic environment for food safety.

How to Use an Airlock for Fermenting Vegetables

Using an airlock for fermenting vegetables is easy to do with the Fermentools system. Each piece in the kit is set up to work together to provide you with the proper tools to produce healthy food in a simple system. Once you have your food submerged under your glass weight, simply place the lid. Fill your airlock half full with water, cap, and insert into your lid.

Always leave an inch of headroom on your fermenting vessel to accommodate any food expanding during the process. For food safety, always remember to clean and sanitize the airlock and plug before each use. Only fill your airlocks with clean water.

This simple tool, the airlock, not only makes fermenting easier but aids in producing safe and healthy food. And who doesn’t want that?


Mindie Dittemore is the driving force behind The (mis)Adventures of a “Born Again” Farm Girl where she inspires others to do more for themselves. Her motto is “It’s not the amount of land you live on, but what you do on that land that makes you a homesteader.” She resides in rural Michigan with her husband and two young country kids, along with a small herd of critters.

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