First Lager - A Question About Tempearture

[cKc]

OK, I'm part-way through my first lager and have just finished a 2.5 day diacetyl rest after 3.5 weeks in primary. I racked to a cube last night for lagering in spare fridge.

After a bit of research I've read you should bring the temperature down "slowly" so as not to shock the yeast when lagering. I.e. don't just stick it in the fridge at 1C (from my ambient rest temp of around 18C).

then, whilst still at 18, rack into cube and put back in fridge, start dropping the temp by 2 or 3 degrees per day, it will take a week to reach your lagering temp of 1 or 2 degrees

http://www.aussiehomebrewer.com/forum/inde...showtopic=32212

2-3 degrees C / day seems like a rather slow drop over a full week. I guess my question is how important is this part of the process to lagering? Is this integral to the process and standard "best practise"? I've read some brewers just go straight from ambient to fridge, switch on their Fridgemate (set at 1 - 2C) and walk away for a few weeks....

 

[cKc]

Whilst not quite answering my original question, the info found here: http://www.herveybayhomebrew.com/art12.pdf is pretty useful. It advocates a slow, controlled reduction in temperatue as most of the brewers here seem to.

Conclusion: I will bring the temperature down 2-3C per day until I hit 1C (patience, grasshopper) and lager for at least a couple of weeks :icon_chickcheers:

 

[A3k]

Hi cKc,
Im no expert in lagering, but the reason for slowly reducing the temperature is to prevent shocking the yeast If you cool too quick, the yeast get shocked and go dormant.

Even though you are done with the primary ferment, you still need active yeast during the secondary to clean up yeast byproducts made during the primary.

Ive been reading a bit on here about it lately though, and theres lots of skepticism about lagering though. Lots of people saying that the diacetyl rest should get rid of the byproducts, and the cold it to clear it. This to me would indicate that after the diactyl rest, active yeast doesn't really matter.
But I havent experimented enough to comment on that.

Cheers,
Al

 

[The Big Burper]

Hi C,


Unless you have a really efficient refrigerator, bunging it in at 2dC should not matter, as the temperature of the wort (assuming 23 litres) will not drop that quickly to shock the yeast. There is a big body of warm liquid there, it will not chill all that fast.

That's what I reckon, anyway. :unsure:

cheers
Dave

 

[cdbrown]

Putting the warm fermenter into the lager fridge will be fine as it'll take a fair amount of time and work from the frigde to cool the brew down. Once ferment is complete I just dial in the new temp on the fridgemate and let it go. With the weather the way it is at the moment it'll probably be down to 2C within 12 hours.

 

[manticle]

I've lagered by putting my fridge on the highest setting and dropping it down over several days. 2 deg a day sounds a bit anal to me and not something I'd bother with. I'm not the world's foremost lager expert but the few I've done have worked out fine using this method.

 

[cKc]

Thanks for the good responses so far!

Anybody have a definite opinion that the rate of reduction in temperature should be at such a slow rate (2-3C / day)? Otherwise I think I'm going to speed up the process. B)

Cheers,
ckc