THE MYTH OF SECONDARY FERMENTATION:
WHY MANY MODERN BREWERS (INCLUDING
PALMER) DON’T RECOMMEND IT
Discussant: Jeremy Kees
Why use a Secondary?
• Remove beer from the yeast cake (trub)
– Autolysis
– To quote John Palmer (How to Brew, 1ed)…
“When a yeast cell dies, it ruptures - releasing several off-flavors into the
beer. When you have a large yeast mass on the bottom of the
fermentor, you have a large potential for off-flavors due to autolysis. If
this ever happens to you, you will know it. The smell is one you will
never forget.”
“At a minimum, a beer that has experienced autolysis will have a burnt
rubber taste and smell and will probably be undrinkable. At worst it
will be unapproachable.”
But consider this…
• In a recent podcast, John Palmer and Jamil
Zainasheff discussed the issue and concluded…
– Secondary fermentation was recommended in the
1st edition of Palmers book (1999) (which is widely
available for free online)
– Health and vitality of yeast is different now (i.e., we
use liquid yeast and make starters)
– YOU DON’T NEED TO TRANSFER THE BEER OFF THE
YEAST TO AVOID AUTOLYSIS LIKE WE USED TO
RECOMMEND
My thoughts
• Leaving the beer in the primary for a month (and
probably 2 months) is not a problem
– The very small risk of off flavors is offset by the more likely
“damage” done by racking to a secondary (e.g., infection,
oxidation) and taking the yeast away too early (e.g.,
diacetyl, acetaldehyde)
– Plus, there is the added benefit of the yeast being able to
“cleanup after themselves” (i.e., metabolizing
fermentation byproducts)
• Use a secondary for lagering, ageing, fruit additions,
dry hopping, etc.
• If it’s good enough for Palmer and Jamil, it’s good
enough for me!!
Remember
• ANY strain on the yeast increases the potential
for yeast derived off-flavors
– Use healthy yeast
– Consider pitch rates (use a yeast starter)
• Jamil’s “Mr. Malty Pitching Rate Calculator”
– Properly aerate the wort before pitching
– Ferment at cool temps (below 70 for ales and
below 50 for lagers)
Equipment Corner
Refractometer
vs.
Hydrometer