Glass Anaerobic Fermentation Vessel




Introduction: Glass Anaerobic Fermentation Vessel


Building an all glass, anaerobic lacto-fermentation vessel is extremely easy. All it takes is the creation of single 5/8″ hole, an objective simply accomplished with a hand drill. If (for some reason) you have access to a drill press, this already rudimentary project is made even easier!


  1. 5/8″ diamond grit drill bit
  2. electric hand drill

Diamond grit drill bits are common pieces of tooling and run about $20. Or instead of buying the bit, check it out for free at your local tool lending library. They totally have drills too! If your local library system lacks a tool lending library, help start one (contact the Oakland Tool Lending Library for tips on this process).


  1. bail-top/French Kilner/wire bail/lightning jar (I use Fido brand)
  2. airlock (comes in one-piece and three-piece variants, either will work)

  3. size 2 rubber stopper with hole OR grommet with the following dimensions: inside diameter 3/8″, outside diameter 7/8″, overall thickness 3/8″, panel thickness 1/8″, panel hole diameter 5/8″ (I use mil-spec silicon grommets from McMaster-Carr part number 1061T27)

Sur La Table is a source for Fido jars. I've also come across glass bail-top jars at Marshalls (side note: Marshalls' food section is fascinating). Airlocks and size 2 rubber stoppers are easily purchased IRL and/or virtually through homebrew supply stores.


  1. drill a hole into the jar's lid using the 5/8″ diamond grit drill bit (center it if you want!)
  2. push either the size 2 rubber stopper OR silicon grommet into/through the hole

  3. push airlock into stopper or grommet


To reiterate, drilling through glass is an easy process IF two simple rules are followed: GO SLOW and KEEP THE CUTTING END OF THE BIT WET WITH WATER. Diamond grit drill bits work by abrading (as opposed to cutting) the glass which is a slow process. The lids on the jars I use are only 1/8″ thick but I spend 90 to 120 seconds drilling out the hole.

This process also generates copious amounts of heat which we want to dissipate. Pouring a constant stream of water onto the grinding bit keeps the glass cool and results in a clean hole.


  • Place the lidded jar into some sort of tub. All the water you'll soon be

    pouring onto the bit will collect in the tub instead of spilling onto the ground. Alternatively, place just the lid into the tub. I prefer to work with an entire jar because the base provides a superb grabbing/stabilization point.

  • Brace the bottom of the drill against a solid, vertical surface (I use a
    table leg). By drilling with a "backstop" like this, the drill's horizontal drift is drastically reduced. The goal is to maintain a 90° angle between drill and lid during the entire drilling process.


  • Right before drilling, begin pouring water over the bit (or even better,

    get a friend to pour!). By utilizing a malleable plastic container for the pouring, one can easily aim the stream directly onto the bit.

  • Go slow. And don't push down. Let the bit do the work. Remember, the diamonds in the bit are essentially sanding away the glass. Sanding takes time.

  • The feeling of the drill will change in the moments before the bit fully cuts through the glass. At this important juncture, resist the urge to push down on the drill in an effort to "finish the job". If you do, there's a good change glass will chip out. But if this happens, IT'S OKAY. In fact, it really doesn't matter at all if the bottom chips out.


You kind of just jam them into the hole in the lid. The grommet takes a little folding.


  • The single piece airlocks fit a little better into the number 2 stopper, and the three piece airlocks fit a little better into the grommets. But the difference is negligible. Work with whatever supplies you can acquire.
  • When using a grommet, push the airlock in until the stem sticks out of
    the bottom. When using a stopper, the airlock's stem will only fit about halfway into the hole before friction completely takes over.

  • Insertion of either airlock is eased if you twist as you push.


We're now getting into fermentation process/theory, a topic best left to the experts. But basically, you want something to hold the fermenting food underneath the brine. I've found two things that kind of work. One is a 3 oz. ramekin (also known as a 3.25″ ramekin) and other is the second smallest pyrex mixing bowl available at Sur La Table.


I'm quite partial to the fermented turkish-fig coconut granola on the Pickl-It site. It's delicious.



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8 Discussions

a good plan for cheap small sized fermentation vessels! but i must warn you, Sur La Table is one of the more expensive kitchen equipment stores. i highly suggest looking at garage sales, marshals, ross, those kinds of places first.

Saved me a ton of $$$! Thanks for the great ible.

Thanks for the detailed instructions! I just made 4 vessels: 2 x 5L and 2 x 2L and plan to make a couple more.

I have a batch of kraut going in a 2G ceramic crock (no airlock) for Thanksgiving. The crock works great, but requires a bit of maintenance during the ferment to keep the top layer of brine as clean as possible. I needed to start another batch for Christmas, so I was looking at another ceramic crock when I found the Pickl-It option.

Since we're big users of the Fido jars in the kitchen, it seemed silly to pay Pickl-It prices when I figured I could do it myself. Pretty quickly came across these instructions, gathered up the parts & equipment, and made my own. I was fortunate to have access to a drill press, which made things a touch easier for me, but looks like drilling by hand isn't a big deal.

FWIW, I tested my vessels to confirm I had tight seals between the jar / lid, lid / grommet, and grommet / air lock. Chucked in some vinegar and baking soda, closed 'em up, and dunked in a huge pot of water (with food coloring so I could tell if any water made its way into the vessel at any point). All 4 vessels released the internal gases through the air lock with no leakage anywhere else. And after pressure equalized, no water made it into the vessel, either.

Can't wait to fire up my Xmas kraut!

Made it according to the example provided, verbatim. Love it. One of my favorite instructables - thanks for putting this together!

Does anyone have any suggestions for getting the output smells under control?

I'd like to ferment some things inside of my home due to limited space and was thinking of getting some bigger poly airlock containers to put my fermenter in but the cost is a deterrent. Any ideas are appreciated.

Very cool

Can you specify the variation of drill bit? that sort of looks like a plug cutter? Thanks! This is cool :)

1 reply

Yes! Diamond grit drill bits cut holes
by abrading away material (as opposed to cutting away material which is
how toothed bits work). This means that using a diamond grit drill bit
is exactly like sanding. So for this project, you're basically sanding
a hole through the jar's lid.

There's a whole host of brittle
materials that would shatter if you tried to cut them but are happy to
be sanding into oblivion. Glass is one such material!

I purchased
the DEWALT DW5580. I've used it to make eleven of these jars plus have
cut drain holes into countless ceramic pots and the bit still cuts
well. I'm sure you could drown yourself in hours of endless internet
debate over which brand retains it's sharpness the longest—or you could
just buy whichever one you see first and start cutting holes in
shatter-y things!