Ask Mr. Wizard

Lagering Length


Dave Wood asks,

I am making a classic style Pilsner and was wondering how long I can lager the beer in the secondary fermenter and in the bottles?  Is two months in the secondary too long?  Should I condition it longer in the secondary or in the bottles?


I think this question probably will generate two very different
answers depending upon who you ask. In this case you asked me and will
get my take on it.  Let’s back up . . . why lager beer at all?  The most
common reasons cited for lagering, or aging before serving, are
diacetyl reduction, acetaldehyde reduction, clarification
and carbonation.

Some folks talk about flavor maturation, flavor mellowing and beer
stabilization when they talk about lagering, but these are all different
terms for the four objectives I cited. The only thing that should be
performed before bottling is clarification, and this only needs to be
done partially since yeast is needed for bottle conditioning and the
bottle bottom serves reasonably well to keep yeast sediment out of the
beer, provided that some care is exercised when moving bottles around
and when the beer is poured.

I suggest fermenting your lager until the final gravity is stabilized
and then allowing it to sit at the fermentation temperature for a few
days to give the diacetyl and acetaldehyde reduction steps a solid head
start, if not more than enough time to be complete. Move the beer to a
cold place, such as a refrigerator or snow bank for about a week.  The
cold temperature will knock a lot of the yeast out of solution and make
racking easier prior to bottling. I then would rack, prime and bottle.

If you want to hold your Pilsner for a couple of months prior to
drinking I would suggest the hold step after bottling because the bottle
has everything you need for lagering; yeast, beer, fermentable sugars
and a mechanism to hold the carbon dioxide in the container (the bottle
cap). This is of course not traditional for lagers. Most lagers brewed
in the old days, which is what brewers often reference when discussing
“traditional” methods, were aged in large tanks or barrels and then
moved into smaller barrels where they would be transported to the tavern
for serving.

Response by Ashton Lewis.