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 1 st 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