Temp Step-down when Lagering, why?

[brewmantic]

I'm about a week away from doing the Diacetl rest and then lagering a first attempt at a Maibock. I'll have use of a walk-in cooler for secondary fermentation, but no real way to "step-down" the temps from 65 (diacetl rest temp) to the 35-40 temp of the cooler.

I've heard that reducing the temp 5 degrees a day until you get it to lagering temp is the ideal. Why is that? Will it shock the yeast to be cooled too quickly? Produce more diacetl? I'm fairly sure I can do it in 2 stages, first to 55 degrees (basement temp) and then to 40. Would that work or should I even bother?

Thanks brew-bros.

 

[pompeiisneaks]

I'm pretty sure it's the yeast yes. You can shock yeast into sleep or even death if you drop temps too fast. I do mine in like 3-5 degree increments over a few days.

 

[duffman2]

I've never stepped down my lagers. I've meant to but haven't done it with the 6 or so lagers I've done. They have all attenuated well and have ended up tasting great. But I'm sure stepping down somewhat slowly would be ideal.

 

[CLBrewer]

I'm doing my first MaiBock as well. The reason I believe you drop the temp a degree or two everyday is so you dont shock the yeast and get bad off flavors due to straining the yeast. As for why to lager it helps to "bright" clear out the beer and helps the flavors mash together. Thats my understanding at least.

 

[JetSmooth]

Why not wrap the fermenter in 20 sleeping bags and remove one a day or so?