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  • 1.  soft crashing/crashing beers after they have passed the target FG

    Posted 11-21-2024 17:10

    Hi all, I have a question regarding best practices for when your beer has reached your target terminal gravity but still shows signs of active fermentation. In the past our brewery has soft crashed tanks to 55F in an attempt to slow down fermentation. We use Berkely yeasts Diacetyl reducing yeast so we aren't as concerned about a diacetyl rest. Is it better to let the beer finish fermentation in its own time at fermentation temperature (66-72F) or soft crash to try and keep the beer in spec. Thanks  



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    Hudson Fort
    Ex Novo Brewing
    Corrales NM
    (503) 201-5325
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  • 2.  RE: soft crashing/crashing beers after they have passed the target FG

    Posted 11-22-2024 13:12

    I'd advise against leaving fermentable sugars behind by trying to manipulate your final gravity by stalling fermentation, even if you are using tools to control diacetyl.  You'd likely still have elevated acetaldehyde levels with that strategy and then have risk of any residual yeast slowing fermenting in package causing unwanted results.  I'd suggest making changes in the brewhouse to change your wort composition and trying to blend to spec if you need to.  My two cents is that the brewer should always have the goal of making sure all fermentable sugars are consumed during fermentation.



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    Jason Weihbrecht
    GM of Brewery Operations
    Oskar Blues Brewery
    Brevard NC
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  • 3.  RE: soft crashing/crashing beers after they have passed the target FG

    Posted 11-22-2024 13:12
    Hudson, by "within spec" i assume you are talking about ABV. Our best practice is to let the yeast do its magic. Even though yeast has a range of attenuation, you can see a pattern and be able to anticipate what your Apparent Extract will be provided your mash temp, Original
    Extract and pitch rate are consistent. Once you know your Apparent Attenuation for each yeast, you can then adjust your Original Extract and mash temp to hit your desired ABV. By throttling the yeasts activity, then you have unfermented sugars that make it to your packaged product and can be more susceptable to bacterial or additional yeast activity resulting in unwanted results like exploding or foaming cans. Be nice to your yeast, it will be nice to you.��





  • 4.  RE: soft crashing/crashing beers after they have passed the target FG

    Posted 11-22-2024 14:33

    Hi Hudson,

    Unless conditioning/carbonating the beer in the final package or other similar procedure it is best practice to allow the beer to finish (i.e.-reach final attenuation) before packaging and even then many breweries will fully attenuate the beer before adding a calculated quantity of sugar (and yeast) to achieve a given carbonation level. Fermentable sugar present in the package can provide fuel for un-wanted organisms possibly resulting in production of off-flavors, unwanted secondary fermentation, package over pressurization, etc. Mentioned previously but I recommend reviewing raw ingredients and brewhouse procedures (particularly mashing/mash program). It could be a simple mash time and/or temperature adjustment to achieve the desired FG/ % RDF. Regarding this, a good quality test to implement would be forced fermentations on your filled fermenters. This is a simple test where basically an excess amount of yeast is added to a sample of wort in a beaker/flask which is placed on a shaker table (or something similar). The idea is that the excess yeast and constant agitation attenuates the wort much quicker than the production fermenter so you know where that should finish out (theoretically, at least). Should be able to find SOP on BA website and definitely on ASBC.

    Cheers,



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    Phil Leinhart
    First Key Consulting
    Cooperstown NY
    (607) 237-4468
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