Ask The Brewmasters

Howdy Fellow Brewers,

In TQ Vol 57, No 1, 2020, pp 19-21 there is a great bit on Managing DO in the Brewery. On pg 19, the author discusses Brite Tank purging, and I would like to get a bit of clarification and/or best practices, per the recommendations in this TQ.

Our SOP is very similar to that explained in this article, specifically: purging from the bottom of the tank for an extended period, albeit at a higher PSI than the 5PSI recommended in this TQ article. In the article, the author recommends 1 hour of purging at 5 PSI per 10 bbls. With this is mind, here are my questions: 

After this low pressure CO2 ingress has gone on for an extended period and the tank pressure reaches ~4.5-5 PSI, would you then recommend very slowly bleeding off the pressure while the CO2 continues to enter the tank from the bottom, expelling the air from the off gassing at the CIP arm? As the author recommends 1 hour per 10 bbls, would the hour start when we begin off-gassing, expelling the air?

Further, after we have off-gassed the tank slowly as mentioned above, the next step would be to increase the tank pressure to 12-15 PSI in order to provide adequate back pressure during the subsequent beer transfer. How do you recommend bringing the tank pressure up to 12-15 from the 5PSI? For example, would you recommend discontinuing the off gassing after sufficient time off gassing/adding CO2 per above, to then increase the regulator by 1-2 PSI every few minutes until the tank pressure is sufficiently high at the 12-15 PSI target?

The major considerations here are to carefully and sufficiently off gas (expel air), then carefully bring up overall tank pressure while avoiding turbulence. In a 15 BBL brite, this entire process to reach 4-5 PSI at 5PSI delivery pressure, then off gas carefully for an extended period while CO2 is constantly added, to then slowly bring the pressure up inside the BBT could easily tank 2-2.5 hours. This is not a problem, and I simply want to ensure we understand the advice and are following best practices for BBT purging.

Thank you for your perspective.

------------------------------
Travis Kocurek
Brewer/Owner
Hound Song Brewing Co.
Columbus, TX
979-942-7199
------------------------------

I recommend this tech tip: https://www.mbaa.com/brewresources/TechTips/Pages/Purging-Bright-Tanks.aspx

It describes varying methods, if you want to do a slow & steady purge for the best Co2 Purity push @10psi into the bottom of the tank, maintaining 5psi on the tank while off-gassing. They list time recommendations but it's hard to follow those as we don't know if they're using high-flow Co2 regulators or the size of the Co2 line itself so that's going to vary brewery to brewery. As far as off-gassing they recommend using an orifice plate but honestly I just use a zwickel to control the pressure on the vent arm.

If time constraints exist I blend the two methods of hard-blow downs & slow & steady, here's an example:

1. Pressurize tank to 15 psi, vent to ground. Repeat this step 3x

2. Pressurize vessel to 5psi, log DO here:

3. Reduce Co2 regulator to 10psi

4. Push Co2 into bottom of tank @10psi and maintain 5psi headspace while blowing down for 1 hour increments

1. Maintaining head pressure on the tank will assure a higher purity of Co2 or less pockets of turbulent air

5. Log Hour 1 DO here:

6. Log hour 2 DO here:

7. Log hour 3 DO here: 

8. Pressurize brite to 10psi once fully purged

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Shane Bird
Brewing Supervisor
JuneShine
------------------------------

Original Message:
Sent: 11-07-2023 13:47
From: Travis Kocurek
Subject: Proper Write Tank Purging (TQ Referenced)

Howdy Fellow Brewers,

In TQ Vol 57, No 1, 2020, pp 19-21 there is a great bit on Managing DO in the Brewery. On pg 19, the author discusses Brite Tank purging, and I would like to get a bit of clarification and/or best practices, per the recommendations in this TQ.

Our SOP is very similar to that explained in this article, specifically: purging from the bottom of the tank for an extended period, albeit at a higher PSI than the 5PSI recommended in this TQ article. In the article, the author recommends 1 hour of purging at 5 PSI per 10 bbls. With this is mind, here are my questions: 

After this low pressure CO2 ingress has gone on for an extended period and the tank pressure reaches ~4.5-5 PSI, would you then recommend very slowly bleeding off the pressure while the CO2 continues to enter the tank from the bottom, expelling the air from the off gassing at the CIP arm? As the author recommends 1 hour per 10 bbls, would the hour start when we begin off-gassing, expelling the air?

Further, after we have off-gassed the tank slowly as mentioned above, the next step would be to increase the tank pressure to 12-15 PSI in order to provide adequate back pressure during the subsequent beer transfer. How do you recommend bringing the tank pressure up to 12-15 from the 5PSI? For example, would you recommend discontinuing the off gassing after sufficient time off gassing/adding CO2 per above, to then increase the regulator by 1-2 PSI every few minutes until the tank pressure is sufficiently high at the 12-15 PSI target?

The major considerations here are to carefully and sufficiently off gas (expel air), then carefully bring up overall tank pressure while avoiding turbulence. In a 15 BBL brite, this entire process to reach 4-5 PSI at 5PSI delivery pressure, then off gas carefully for an extended period while CO2 is constantly added, to then slowly bring the pressure up inside the BBT could easily tank 2-2.5 hours. This is not a problem, and I simply want to ensure we understand the advice and are following best practices for BBT purging.

Thank you for your perspective.

------------------------------
Travis Kocurek
Brewer/Owner
Hound Song Brewing Co.
Columbus, TX
979-942-7199
------------------------------