Too long in Primary Fermentation?

  • What's the maximum amount of time for primary fermentation, assuming the beer is going straight to bottles next? Will it over ferment and then fail to carbonate, if left too long in a carboy?

  • It takes three to nine days for yeast to ferment a typical wort. After yeast consumes all the available food (or produces too much toxic alcohol) it goes into a dormant stage, flocculates and drops out of suspension. At this point it does not produce alcohol or CO2. Priming sugar is used to give the yeast a little more fuel so they will wake up and carbonate the bottle. This means that you can not over-ferment your beer.

    I do not transfer my beer from primary. You can leave them for months with little flavor impact.

    The danger of off-flavors caused by leaving beer on the yeast cake for too long is something of a boogey-man. The biggest concern is autolysis which produces flavors starting at "yeasty" & going through "meaty" to "rubbery". I left a brew on the yeast for *six* months without negative impact. This is, of course, anecdotal. I get some of my information from Basic Brewing Radio and The Jamil Show.

    I've heard that autolysis is usually only a problem in commercial breweries, because the weight of hundreds of gallons of beer focused on a small yeast cake in a conical fermenter will actually kill the yeast.

    @TMN, could you give us some clues, where you can be heard this ? I'm interested to research about this.

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Content dated before 6/26/2020 9:53 AM