Diacetyl Rest

[slamback]

I'm lagering a Czech Pilsner now (my 1st solo lager effort), and have a question about the diacetyl rest. I'm a bit unsure whether I need to do one - my question is will it hurt anything to just do it anyway? The OG was 1.053 and after 8 days at 50 deg F it's down to 1.016. I'm thinking if it won't hurt, I'll bring it up to about 58 for a couple of days then rack it & bring it down to lagering temp for a couple of months. Is there any downside to: a) keeping it in primary until FG is reached before diacetyl rest, or b) doing a dicetyl rest if one is not needed. I can't really taste any butter flavors, mostly green...

Suggestions? Thanks!

 

[samc]

I'd do the rest and no it won't harm anything to do it if not needed. I've always read that it is best to do it after the beer is 75% finished in its fermentation. Sometimes those subtle off flavors don't show up until you have carbed and chilled the beer, that has happened to me and it was very subtle, maybe somewhat to style but I didn't like the finished product.

 

[bannonb]

I would do it. You'll have 3 months into this beer before it's ready to go...go through the step and avoid any diacetyl if you can.

I did my diacetyl rests right after primary. I took it out of the fridge and let it sit for 48 hours at 67-68. Fermentation kicked in a bit, getting the last bit of sugar and diacetyl (if any) out. Then like you say, into lagering.

 

[TopherM]

Diacetyls have been extinct, along with all of the other dinosaurs, since the Mesozoic period.

SILLY!

 

[slamback]

It is resting comfortably at 58 degrees at this moment. Then begins the slow downturn of temperature. See you in September!!

 

[ayoungrad]

I have done one pilsner only. I did a diacetyl rest that took one week to clear the buttered popcorn aroma/taste when using the test for diacetyl described elsewhere on this site (heating one sample and cooling another). I did the rest prior to final gravity.

My pilsner turned out great. No idea if it would have without the diacetyl rest but I can say that there was definitely diacetyl at the time I did the diacetyl rest despite no hint of diacetyl in the sample I tasted at room temperature from the fermenter just berfore starting the rest.

 

[AmusedBystander]

I think a couple of months of lagering is a bit much. It's a pretty light beer, I don't think your going to get much benefit from extended lagering. Just my $.02

 

[King of Cascade]

I think a couple of months of lagering is a bit much. It's a pretty light beer, I don't think your going to get much benefit from extended lagering. Just my $.02

I agree...there is a lot of hop character that is best when fresh the only thing IMO aging will do is fade out the hops. Our local Gordon Biersch makes an awesome german pils and I have had it unfiltered out of the fermenter and it is a totally different beer.

 

[bhaff]

I am working on my first lager. I picked a "session" lager from NB. Their Tmave 10 recipe. I plan to do a d rest but I'm not sure when to start. My OG was 1.039 and my final should be around 1.011. I imagine I will d rest once I get close to 1.017. I fermented at 56-58 it took a while to figure out the difference on my analog controller so I might have been a tad warm for the first day. Does 65 for a d rest sound good?

 

[steinsato]

slamback, I could be wrong but I don't think 58F is a diacetyl rest. You need to get that beer up to the mid 60s to get rid of diacetyl. I don't know what yeast you used but my czech pils yeast says to ferment from 50-58F. It's been fermenting right around 53F for a week now and the room smells like sulfur. I'll probably give it another week then bring it up to around 65F for a few days for the D rest. Then back down to 53F for another week or two, then keg and lager for a month.

 

[permo]

To play devils advocate here, I usually give my lagers 4 weeks of primary fermentation with no D-rest. Diacytel has never been detected in any of my lagers.....

 

[Tamarlane]

To play devils advocate here, I usually give my lagers 4 weeks of primary fermentation with no D-rest. Diacytel has never been detected in any of my lagers.....

Well some recommend pitching cold and fermenting at the lower end of the yeast's optimum range and you can skip the diacetyl rest. I prefer to skip it unless I taste diacetyl in the sample but if folks want to do it to be on the safe side it can't hurt anything. I use a water batch for temp control so it is a pain in the ass to change temperature from 50ish to 65 and then back down to lagering temps. I say if you have a fridge and temp controller its as simple as turning the dial so why not?