A question I would ask is "How long are you going between brews?" The procedure you've listed here should be sufficient for many applications. I would go so far as to say, if you're a small brewery and brewing every 2 days then you're probably at a sufficient level already.
If you're a small brewery that--for some reason--relies heavily on long-range distribution and >1 month reasonable-shelf-stability you might need to do more. Let's assume this brewery is small and does mostly draught you probably don't need to do any more than you are--excepting that I would make a schedule for a full HX teardown.
My personal preference is to treat the HX as you have been, but doing the most intensive clean prior to use to limit the time for microbes to reproduce: use it as you have been but then perform a full CiP including caustic, rinse, PAA, and possibly another rinse immediately prior to use. (A further question here is "How hot is your HLT purge?" I like to have the HX be physically hot to the touch from the outside before I'm satisfied with the hot water purge.)
I also got into a habit of drinking a cup of sample water from the HX final rinse prior to it's use: if I don't feel it's not safe for me to drink from, how could I ever expect a customer to think so? It was a habit that prevented some junior brewers from running roughshod over procedures, and helped drive home the important of purging and verification.
I would further recommend one or two spare gaskets for the HX to facilitate easy strip down and reassembly (you don't want a broken gasket to end your day!).
Now, if we wanted to get more technical, or assume that your brewery is larger and will require more distribution and longer shelf life.... First thing I would comment is that the warmer the ambient temperature of the brewing area, the faster microbial infections will grow during downtime. This is to say that a procedure for a brewery where the brewhouse is cold overnight (rural Canada, where I am), might not suffice for a brewery in a warmer place during the summer (Texas). Packing the HX with PAA isn't exceptionally problematic--excepting that junior brewery staff have a habit of over-concentrating the PAA. There are other relatively mild solutions that will offer similar protection, and you are right to fear for your gaskets!
There's also the safety consideration of leaving the HX pressurized with a potential irritant agent rather than say, hot water which will eventually cool. "What will happen if someone kicks this valve? Can I trust my staff to manage tour-goers safely? How well-trained are the people who use that space? What happens if it spills?" All of these are questions that have nothing to do with microbial safety, but should also factor into your thinking about total-risk-management. For example, if you have a HX packed with CiP solution there might be enough volume that you should really have spill containment considered before leaving the building. Whether or not these concerns can be addressed will depend on your particular situation, and I will refrain from generalizing.
I hope some of that helped.
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Matt Philip (WeCanDrinkTogether)
Severn ON
(519) 588-3242
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Original Message:
Sent: 08-15-2023 18:20
From: Travis Kocurek
Subject: Heat Exchanger SOP
Hello,
What is your recommended best practice for packing the HX post-brew? In our case, we brew generally once per week and I am looking to find the best way to pack (and store) the HX during this time.
I am avoiding packing the HX with PAA to avoid gasket damage. I am also concerned that leaving the HX and associated process piping packed with plain brewing liquor is also not the best idea, as this might allow biofilms to develop.
Presently, our SOP consists of purging the HX of wort in both directions with HLT water post-KO, running a caustic loop in both directions, then we conduct an additional purge with HLT water in both directions as a final rinse.
Would you recommend simply blowing out this final rinse water with CO2 and then sealing the HX and process piping while mostly empty? Alternatively, would you advise packing it with something else? Perhaps a non-caustic alkaline cleaner (like PBW or similar)?
Thank you for your perspectives!
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Travis Kocurek
Brewer/Owner
Hound Song Brewing Co.
Columbus, TX
979-942-7199
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