Universal Fermentation Airlock




Introduction: Universal Fermentation Airlock

This instructable shows how to add an airlock to almost any hermetically sealed container.

Step 1: Tools and Materials Needed

The tools and materials needed:

An airlock

1/4" plastic tube

PG 13.5 mm cable glands

A step bit or a 1/2" knock our punch

3/4" rubber washers

Total cost of consumables for one mount < 5 dollars.

Step 2: Make a Hole on the Lid

Use the step drill or the knockout punch to make a hole on the lid of your container.

The optimal hole size is one that the threaded end of the cable gland can barely fit through.

Step 3: Mount the Cable Gland

Pull the rubber gasket on the threaded end of the cable gland.

Insert the cable gland and tighten the nut with a wrench.


Silicone rubber is a better sealer then a normal rubber gasket but I didn't want to open a tube of silicone for this project. If you have silicone rubber at hand feel free to use it :)

Step 4: A Note on Airlocks

Some airlocks may have edges left from the manufacturing process. You may have to sand them of to ensure an hermetic seal.

Step 5: Have Fun With the Variations and Create a Jumbo Air Lock

Try out the flexibility of this method :)

I only used 1/4" tubes here but if you use a bigger cable gland you can easily mount a 1" tube on your container.

Here is the video that I got the idea from (now these are some serious fermenters !!!!)

Have fun with your fermenting :)

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    7 years ago on Introduction

    This is great! Can this work on metal lids? I have a large pickle jar that I would love to turn into fermenters, but the lid is made of metal.


    Reply 7 years ago on Introduction

    Yes it works. The pickle jar you see in this instructabel also has a metal lid. I strongli suggest using a step drill for that.

    Thanks for the idea. I will make an instructabel also on making large pickle jars into fermenters (If you want to write it tell me so I wont steal your idea :) )


    Reply 7 years ago on Introduction

    Oh, don't worry about waiting for me to make an instructable for this; I'm sure converting a large pickle jar is not a new idea. Good to know this works on metal lids.


    7 years ago on Introduction

    Really great info! Thanks for sharing and welcome to the community!