One Way Valve Jars Home Made

Home made 1 way valve jars

Update, I seem to have found an even better method see Vacuum Packing At Home

I have found that if you can pack coffee correctly within 1 hour or so of roasting, it can give GREAT results. This is born out my my Naked portafilter videos with a 9 day old bean. If you pack into a standard jar, as the pressure builds, the gasses remain in the jar under pressure and the Oxgen also remains. Under pressure , oxygen will be even more reactive and the staling process will actually be enhanced. The idea of the one way valve at the top of the jar is to allow the oxygen to be flushed out.


Beans give out Carbon Dioxide (CO2). CO2 is heavier than Oxygen so sits at bottom of jar and effectively all the oxygen in forced out, because the valve is at the top, (unlike a coffee bag). CO2 acts as a natural preservative for coffee. All this of course only does any good until the moment you open the lid. For this whole thing to work succesfully, the jar has to be as full as possible and sealed up whilst the beans are degassing and before oxygen has a chance to start working on them. So it's for the longer term storage of beans, but normal staling will begin the moment you break the seal, obviously the staling/rancidity will still happen in the jar, but it is slowed down.

I have had beans in a Valve bag (overfilled slightly) sealed correctly and degassed at an angle. I have opened them after 3 weeks and they are pretty good…BUT packed within an hour or so after roasting.

At no time keep the beans in the fridge or freezer, in my experience this ruins the taste.

So on to the project:

The early ideas (some successful, some not but I would use sticky tape and not a glue gun next time!)


I tried using storage jars with clip down lids. The acrylic tops were hard to drill and prone to cracks as you can see. Other similar jars have steel tops and these would be hard to drill. Tape was used to seal the valve in and seal the cracks.

The downside of this method is the difficulty to make and the cost of the jars. Not recommended.


I have always been interested in recycling and thinking about an environmentally friendly method, led me to the final, and I feel most suitable method. The use of old food jars, these can be small jam jars, or quite large pickle/mayo jars with metal lids (the lids are thin and easy to drill/grind). It's not only free, but good for the environment as these things are normally just thrown away.

My first "recycled" 1 way valve jars. I had 3 old jam jars and successfully made them into 1 way valve jars. I am quite pleased, because this is one of the big areas of recycling "reuse" and anyone who knows me, also knows, I try to take the environment seriously (I even have an eco-car ).

I suppose jam jars are in a sense an ideal size as it allows long term storage of smaller portions of a roast, each portion only being exposed to oxygen by opening ("breaking the seal") when you need to start using it.

For those who want to try making some, the "manufacturing" process is quite easy.

Tools required

  • Clear Sticky Tape (I used a Hot melt glue gun, but the glue doesn't hold properly on metal, tape is better)
  • 6-8mm metal drill bit
  • Small drill mounted grinding stones (use a conical one), Focus DIY sell 5 stones in a blister pack for £1
  • Jam Jars with metal lids
  • Some old coffee bag one way valves (cut from pack, just cut a square incoporating the valve body, easier to seal)


  • Drill lids of jars (use block of wood to support lid)
  • Enlarge and deburr hole by using conical grinding stone in drill (both sides), enlarge hole to about 10mm
  • Tape one way valve to lid. Be mindful of the way the air needs to flow!

That's it, you are done. It takes around 10 minutes to do 3 jars. If you ever need to change the valve, the tape comes off really easily.

Why I like these:

  • Recycled
  • Airtight
  • Washable (except lid)
  • Easy and quick to do
  • Valve can easily be replaced if necessary
  • Cheap/Free
  • Allows CO2 gas to push oxygen out, preserving coffee for longer (Oxygen can get trapped in top of valve bag).

I was thinking about searching for a different type of valve a more high quality brass, spring and o ring type affair. Not sure what yet, but have my thinking cap on…..for now though, old one coffee pouch one way valves will have to do.

An Alternative I also like very much

Last week Paul L showed me some of the new 1 way valve jars he had been making, using Lock & Lock food plastic food containers (with a gasket in the top so they are air and water tight. I was quite impressed and we took some photos of them being made and of course improved our technique still further.

These are definitely a big improvement on my "jam jar" designs and the Lock & Lock containers have the advantage of being simple, cheap, washable, reusable and as we will see later, require only the minimum of tools.

For those who want to try making some, the "manufacturing" process is quite easy.**

Tools required

  • 14mm wood bit (about 70p)
  • Sticky Tape (about 60p)
  • Old one way valves (free?)
  • The Lock and Lock containers (about £3 each)


Use the cheap wood bit, funnily enough the cheap one actually makes the hole by hand in the lid. NO drill required, just twist it around.


Make a SMALL hole and tape the valve in on the underside of the lid. Cut the valve leaving a square surround of foil (it's easier to get a seal using only 4 pieces of sticky tape, cutting a round circle of foil although nice looking, is actually harder to seal)


The finished product….note how the hole is smaller, because it only needs to be large enough not to obstruct the air holes in the valve (it doesn't need to accomodate the valve body now). We used a 14mm cheap as chips wood drill bit, which is just visible in the picture..