Charlottesville Area Masters of Real Ale

I have a Maibock/Helles fermenting right now and it had an original gravity of 1.064.  It has been fermenting for 9 days and the gravity is now down to 1.026.  I'm getting bubbles every 7 seconds.

I'm a lot less experienced with lagers.  Should I let it go for another few days at its current 52 degrees, or should I bump it up 10-15 degrees right now for a diacetyl rest?  How long do you think a diacetyl rest should last, or is it over when I'm closer to 1.016?

Damn.  Ales are so much easier.

 

Did you taste your sample when you took your last gravity reading? If so, did you perceive any diacetyl? If you did, it may be a good idea to go ahead and bump up now to 60 for 2-3 days. If not, it may not be necessary, but probably not a bad precautionary measure just the same. Just my two cents.

I did the gravity reading last night and it tasted fine to me.  It was very clean and yeasty.  (Not sure if those go together but there you are...)  No butteriness, no sulfur, no off flavors. 

I'm just being a little paranoid since I had an Oktoberfest last year that pooped out so I'm watching the last 0.010 pretty intensely.

Thanks for the advice BarleyP.  I think I will let it warm up and blow off a little.  The increased activity at the end might be all psychological but better safe than sorry.

Like BarleyP, I also taste my lagers for diacetyl before doing a rest because sometimes it is not necessary.  When fermentation is 75%-80% complete, I start sampling. The rest shouldn't hurt you either way. I also bring my temperature down slowly after a 2-3 day rest to my lagering temp. It looks like you are all over it though. 

I'd let it be at 52F for a bit longer.  I get nervous about warming up the temp of lagers because of the potential for them to produce some fruity esters.  At 1.026, you still have a fair amount of unfermented sugars in there.  Why not just let it go at 52F for a month in primary?  That way the yeasts have plenty of time to finish out the fermentation and clean up any byproducts like diacetyl.  That's my opinion for whatever it's worth.

Noonan suggest in his book (new brewing lager beer) to do a secondary fermentation around 40 to 41 degrees for 7 to 21 days. During this time the yeast eats up some of the dextrin’s and reabsorbs and diacetyl. At this point you can then drop it to 32 degrees for lagering. A diacetyl rest is good to speed up the time needed for lagering and secondary fermentation though.

Thanks for the advice everyone.

Schneehagen - I've been meaning to check out Noonan's book, but haven't.  I still go back and forth about what temperature I like to pitch my yeast at (both the starter and the wort temps) for lagers. This time, I pitched at 60 degrees and then dropped it down to ~52.  Next time, I'm sure it will be slightly different until I figure out what I like the best (and this way has worked out fine thus far.)

Thanks!

I followed the Jamil and John Palmer advice and pitched cold (~ 48 F) and let it ferment until there was a bubble once per minute or so, then ramped the temp up by ~10 F.  Once the beer finished fermenting, I lagered it at ~38 F (the coldest I could get my weak fridge to go) for about a month.  The beer turned out very good, though when bottles are first served, there is some protein haze.  I think if I had lagered colder for longer, that would have been avoided.

Finish the ferment at 52 deg. F.  Let it stop bubbling.  The whole purpose for a diacetyl rest is to allow the yeast to re-metabolize the Diacetyl into the non-human-perceptive compounds: acetoin and 2,3 butanediol, which have no flavor or aroma character.  Finish the ferment, up the temp to the high 60's for a few days and then lager/cold condition.  If you want, do a taste test before lagering to make sure you have metabolized all of the diacetyl.  Get R Done!