What you will need:

Adjustable Pressure Relief Valve (PRV)

This is the core piece you will need to build a spunding valve for pressurized fermentation. It works the same way the PRV on a Corny keg works, but, instead of being set to release at a specific pressure (which is somewhere around 120 I believe) the point it releases pressure can be adjusted. If you look closely you can see markings along the white body of the PRV and there are even numbers for every 10PSI on mine. DO NOT TRUST THESE. They are very inaccurate and can even differ between uses. Which brings us to the other main piece you will need…

Air Pressure Gauge



I already had an extra pressure gauge from another project but they are all fairly similar. I would suggest something that goes to somewhere around 30-60PSI to get the best accuracy when reading the gauge. I chose to link this one because it uses the same threading as the PRV and would be much prettier than my Franken-Valve .

T-Fitting and a Barb or other plumbing.

Really, there are countless ways to string together these pieces but at the bare minimum you will need some kind of splitter (T or Y Fittings for example) so that one goes to the PRV and the other to the Gauge. And an input such as a barb which can be attached to a gas line leading from the keg. As you can see my Franken-Valve has quite a few connection points. I cannot emphasize enough the importance of using plumbers tape and to check for leaks. Once you get all your parts together and connected take some Star-San solution and spray every connection. If you see it bubbling there is a leak and its best to completely redo that connection.

All together the parts added up to $32.08 USD from amazon. But I’m sure there are cheaper ways to get all the individual pieces whether it be from eBay or cannibalizing other project like I did. There are even a couple online vendors that sell spunding valves setup and ready to go. Although, from what I have seen, these only go up to a max of 15 PSI. Either way you decide to go, you can expect to spend about 30$ to get setup for your first pressurized fermentation.