The Sterilock Airlock

I recently had the opportunity to try out The World’s First Antibacterial Airlock – Sterilock.

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Sterilock’s director, Richard Cook, sent me a basic Sterilock setup. I received the Sterilock airlock, an odor absorbing capsule and two different style lids. Along with a food fermentation guide.


So I set out to make a batch of my fermented cabbage as I usually do. The cabbage was chopped and mixed with a little salt. Then packed it into a jar, topped with brine and sealed with the Sterilock airlock.
I placed it into my usual fermentation cabinet and waited 2 weeks.
My first comment is that I was not able to tell how active the fermentation process was happening as I didn’t have a fluid filled airlock to provide visual feedback (bubbling action).

I did not use the odor absorbing capsule as I usually don’t have an odor issue. So I can not comment on its effectiveness. 2016-04-19 12.00.42

The Sterilock was very easy to use. No need to monitor the fluid level in an airlock, just make sure that the brine level in the jar remains high enough to cover all the fermenting materials. It is a nice compact unit that makes storing the fermenting jar in tighter quarters than possible with a bubble airlock.

But I miss being able to tell if the process is actively working and or has stopped.

This batch turned out to be NOT as sour as I expected. I don’t know if this is because of the Sterilock or maybe the cabbage. I just don’t know.

I also feel that the cost is a bit high compared to the alternate airlocks available. But hopefully with increased sales and production, the cost per unit will drop sufficiently.

But check out Sterilock for yourself and see if it works for your application.

How to make an Airlock Cap


This was the start of my first airlock cap attempt.

I new that I was not satisfied with our fermenting set up.  Not the antique 2 gallon crock nor the one gallon glass jar with glass lid.  The mold and scum, while expected, was not acceptable.  Internet research had turned up fermenting systems that used an airlock but I was unwilling to spend what they where asking.  So we set out to make our own airlock system.

I started by buying a half dozen, half gallon, wide mouth, Ball mason jars.   3capsThen I found a local beer making supply house that sold airlocks.   So my first airlocks where constructed using the standard wide mouth two piece canning lids,  a couple of varieties of airlocks and some tight fitting o-rings to seal the airlock to the lids.   I also used one piece metal lids saved from grocery store products that fit standard Ball canning jars.

From these first tries I found that the o-rings did not seal well enough by themselves.  And the 2 piece canning lids where not convenient to use during fermentation.   All the metal lids tended to develop rust spots after repeated usage.   And the one piece “S” shape airlocks where too difficult to clean.



That brings me to my present, and very acceptable, airlock cap system.   The o-rings have been replaced with 100% silicone sealant.   This needs to be food grade silicone,  no kitchen and bathroom silicones with mildewcides.   Most, easily found, aquarium 100% silicone sealants are food grade.  But check the ingredient list.


ballcapThen there was the rusty metal lids.  These have been replaced with plastic lids made by Ball.

They come in wide mouth and standard mouth sizes.  I found them at my local grocery store along with the other canning supplies for about $3 per box of 8 caps.   These are also very handy to use to cap the fermentation jars after they are done fermenting and need to be stored in the refrigerator.  If not found locally, they are available on EBay.

airlockAnd for the airlock itself, I have settled on the 3 piece design made by Buon Vino Mfg.- Canada.   It is inexpensive and the unit comes apart for cleaning.   These cylinder airlock units are carried by most beer and wine making supply stores.   I have also seen them for sale on EBay, just search for “airlock”.   Locally they cost me $1 each.




The actual construction of the cap system involves drilling a hole in the center of the plastic cap.  The three piece airlock shaft has a slight tapper, so the hole is sized such that the airlock fits snuggly when inserted to a depth of about half an inch.


A bead of silicone is then applied around the shaft both on top of the cap and then on the underside as well.   Wait a couple of days for the silicone to completely cure before using the cap.

And that is the airlock cap design I am presently using.

Future design changes:  grommetMy next version will incorporate a grommet seal instead of the silicone sealant.   I hadn’t already gone this route because of the cost of the grommets in small quantities and the fact that I could not find the correct size locally.   I’ll post pictures when that design change is made, but until then I’m satisfied with the performance of my current airlock caps.


Final design upgrade using rubber grommet.


 I just made my final design change incorporating a rubber grommet to hold and seal the air-lock into the plastic cap.  Picture shows completed design with an extra grommet on edge. 

Found an online site that sells them in small quantities for a reasonable price.

Love this design.