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  • 1.  Cold Crashing best practice

    Posted 08-11-2023 17:06

    There has been some discussion in our brewery as to whether or not we should close the blow-off valve on our 20 bbl fermenter when we cold crash. On one hand, not closing the valve could let sanitizer and potentially oxygen into the fermentation vessel. On the other hand, closing the valve could pose the risk of yeast autolysis or a collapsed tank. What do you do at your brewery when cold crashing a beer< and what are your thoughts on these concerns?



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    Brandon Fair
    River City Brewing Co
    Wichita KS
    (316) 706-0299
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  • 2.  RE: Cold Crashing best practice

    Posted 08-11-2023 17:26

    Hey Brandon, 

    By the time we are green lit to crash, that tank would have either been pitched from or we drop yeast out as much as possible. We seal up the tank and add head pressure (about 8-10 psi), if it was not already spund'd. Our tanks don't hang out more than 3-4 days crashed, before they're spun (centrifuged). That's our process for cold crashing in a nutshell.  



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    Eddie Padilla
    Production Manager
    Smog City Brewing Co
    Torrance CA
    (310) 320-7664
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    Original Message


  • 3.  RE: Cold Crashing best practice

    Posted 08-13-2023 21:36

    For us it depends on the beer and the dry hopping temperature.  If the beer has been dry hopped at fermentation temps or if there was no dry hopping planned then it has 8-10 psi before starting to crash. 

    If, like we have recently been doing for some beers, we plan on dry hopping at 3-4°C we will apply a slight amount of head pressure (1-2psi) during the crash.  When we reach the set temperature and release pressure we will do that very carefully with an eye on the blow off hose to make sure we still have positive pressure and don't suck up any sanitizer.  

    If we are doing a multi-day slow crash then we typically apply the slight head pressure, drop the temp by 2°C, release the pressure and then repeat the following days until we reach the dry hop temperature.  It is a bit of a pain but we don't want the beer to have 4-5 days with head pressure and building up carbonation that will then be later released when we dry hop.  Not sure if this is really an issue or us just worrying too much.  



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    Patrick Brown
    Brewer
    2nd Story Ale Works
    Tokushima, Japan
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    Original Message


  • 4.  RE: Cold Crashing best practice

    Posted 08-14-2023 13:48

    We also bring the tank up to 10-15PSI before crashing if it hasn't been bunged or spunded already before crashing.



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    Ivan Dedek
    Brewmaster/Food Scientist
    Meier's Creek Brewing
    Cazenovia NY
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    Original Message


  • 5.  RE: Cold Crashing best practice

    Posted 08-15-2023 13:26

    You should never crash a tank without positive head pressure at all times, so neither scenario is acceptable. Head pressure on a 20BBL tank shouldn't have much effect on any yeast remaining in the tank assuming you have already cropped the yeast that has settled after primary fermentation, so I would not be concerned about autolysis. 

    We generally bung tanks at the end of fermentation (or 1-1.5P above terminal for non-DH lagers) to 1 bar pressure and hold that pressure until the tank is emptied, though I have also been experimenting with leaving the blowoff open after DH for beers that are prone to larger amounts of hop creep (and the jury is still out there compared to creeping under pressure. It might be a yeast strain-dependent decision). This allows us to retain significant natural carbonation, even for ales. We always double check to make sure we are still at 1 bar prior to chilling a tank.  



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    Sam Tierney
    Propagator Brewery Manager
    Firestone Walker Brewing Co
    Marina del Rey CA
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    Original Message


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