Best Lagering Practices

Well, if you're already at terminal gravity, what kind of "fermentation" could be happening? As for "conditioning," what did the reports say was happening?

 

Let's say for the sake of argument that yeast are capable of absorbing significant amounts of esters and sulfur compunds at very low temperatures. (I've never seen anything scholarly that says they do.) But even if so, they would do it faster at higher temperatures, which is why fermentation and cleanup should be complete before lagering.

I'll add that if a lager has excess esters that need to be cleaned up, something was wrong with the fermentation temperature, or pitch rate, or yeast health, etc. Also, I'd bet a dollar that any reduction of sulfur compounds (H2S) at low temps is because of oxidation reactions, and not due to yeast activity. But these reactions also happen faster at higher temps.

I think a lot of the lore of lagering magic comes from the old lager tradition of long term cold storage of beers that weren't really finished when the temperature reduction started. To my knowledge, there's no process that happens faster in beer at cold vs warm temps except for precipitation of certain solids.

 

I can report that for the 80+ batches of lagers I produced using cold crashing there were no issues with the yeast. I bottle condition my lagers and even after a month+ of lagering the yeast completed the bottle conditioning process just fine.

Cheers!

 

Well, that is the answer right there. You don't need some paper to give you an answer.

Cheers!

 

Yeast choice is a big factor

there are certain strains that ferment well sub 50 and there are ones that ferment better around 52-54.

liquid versions of 34/70 and 2206 variants are great at colder temps

Augustiner and Andechs strains are better around 52-54

If you pitch a ton of yeast and can add sufficient amounts of oxygen there should be no real reason to ramp the temp above 50 for the colder strains and above 54 for the warmer strains as you shouldn’t see lots of diacetyl or acetaldehyde. The slightly raising of temp does tend to help with sulfur reduction in my experience. That being said raising to higher temps doesn’t really hurt anything, it’s just not necessary.

If you’re not adding a sufficient amount of yeast and/or don’t have the ability to add the correct amount of oxygen then yes you might need to ramp to higher temps as your yeast will have a lot more unwanted byproducts to clean up. It’s easy to do forced diacetyl tests to see if precursors are there. You shouldn’t really be detecting high levels of acetaldehyde and if you are the likelihood of yeast clean that up aren’t that great. Easy solution there is to krausen the batch with a small starter.

If you can’t make a starter and don’t have the ability to add oxygen then dry 34/70 pitched at minimum 53 is the best route. It Doesn’t need to go above 58 in my opinion. Wort strength and other variables might come into play.

In my opinion lagers always benefit from slow cooling regardless of what temps they got to. Maybe if you ramped above 60 then 5* per day is fine. If you’re sub 60 maybe 3* per day. I always recommend a week at 40 before cooling down as cool as you can go for as long as you see fit.