Friday, May 5, 2017

Blow off set up....

With the blow off valve open and the tubing inside a jar of Starsan
 it provides a 1/2" blow off during fermentation.

Thought I'd share this blow off set up a friend of mine made up for his SS Brewtech fermentors that I've made and used.  I've found it works great and figured some people may find it useful for their Brew Buckets.  This set up can be used as a blow off tube, a way to perform a pressure transfer, and purge with CO2 while cracking the lid.

Click on the pictures to get a bigger view.

To do as close to an O2 free transfer as possible I'll suspend my bagged hops in a keg and purge it several times with about 20psi of CO2 and then pressurize the keg after purging.   When I'm ready to transfer, I'll hook up my CO2 to the gas fitting on top of the "T" and get the gas flowing at under 5psi to slowly bubble the Starsan in the blow off jar.  The transfer tubing I use has nothing on one end and the other end has a liquid quick disconnect installed on it.  Right before connecting the open end of the transfer tubing to the racking valve on the fermentor, I'll connect it to the liquid out post on my keg.  This releases the CO2 from the keg and purges the tubing.  I then open the pressure relief valve on the lid of the the keg, connect the tubing to the racking valve, close the blue handled valve on the blow off set up and open the racking valve to start the transfer.

To purge the head space while adding hops or other additions first connect your CO2 to the gas fitting making sure the CO2 is off at this point.  Open the two front spring clamps and turn the gas on to about 5psi and close the blue handled valve on the blow off.  You can now lift the lid a bit and make an addition to the fermentor.  Once your done, lower the lid, open the blue valve again, and close the two spring clamps.  You can run a bit of gas though the head space afterwards for a few seconds to further assure you've purged as much O2 as possible.  While I don't open my Brew Bucket during fermentation, this is the method my friend uses to do so.

All the parts were purchased at Brew Hardware except one from SS Brewtech.  The stainless parts are listed from left to right as in the first picture above:

From the lid:
Hose Barb 1/2" 90° for Blow-Off
Left side of "T":
Hose Barb, 1/2" Male NPT x 5/8" Hose ID

And "T":
NPT Tee Fitting Female 1/2" NPT

Top of "T":
Hex Reducing Bushing 1/4" FNPT X 1/2" MNPT

NPT Male, 1/4" to Keg Post Adapter 19/32" -18 Thread

Gas Side Ball Lock Keg Post (19/32"-18) with Universal Poppet

Right side of "T":
Mini-Ball Valve 1/2" Male/Female

Hose Barb, 1/2" Male NPT x 5/8" Hose ID

And then enough tubing to make your top connection and then to reach the blow off jar:
UltraClear Silicone Tubing by the foot, 1/2" ID x 3/4" OD (1/8" Thick Walls)

The 1/2" tubing fits real snug over the 5/8" hose barbs and won't blow apart with the amount of pressure applied during a transfer.  Also, I used some Teflon tape on the threaded parts of the set up.  To clean the set up I remove the tubing and soak the assembly and tubing in PBW for at least 30-40 minutes.


  1. Did you cold crash with this setup? If so, how did you handle that? Rig looks great. Just purchased all of the parts for my 7 gal brewbucket

  2. My also curious about cold crashing?

  3. Fantastic, work perfect, very happy

  4. Good job this. I have built it but had a lot of gas leaking through the lid of the brewbucket under the higher pressure. Did you ever get same?

    1. How much was your PSI? You only need 1-2 PSI to to effectively xfer. Anything more isn't needed and also would be above the Brew Buckets PSI rating.