Do I need a D Rest? WLP810 pilsner @ 50-55 degrees

[bobish]

About 8-9 days ago I brewed my first pilsner/lager...it's been fermenting out side maintaining temps between 50 and 55 degrees.

I pulled a sample yesterday day the OG was down to 1.024 from 1.068, It's still fermenting and tasted great.

My question is if I don't taste buttered popcorn at this point to I need to do a D rest? Can I just let it finish fermenting then cold crash it, keg it, then lager it?

 

[Cyclman]

I would, diacetyl can show up later. Plus, you might get a few more FG points out of a D rest.

 

[bobish]

Ok so by the looks of it I'm right where I want to be to do the D rest.

So now I just bring the carboy inside and let it get up to 65 degrees (it's currently at 54) for 24 -48hours or so before I cold crash and keg it. Right?

 

[GuldTuborg]

What temp did you pitch at? Pitching warm and cooling to fermentation temps seems to give more diacetyl. If you pitched below or at fermentation temps, I'd expect much less. Whether you want to warm at the end is up to you, really. If will affect cleanup, fermentation speed, and perhaps degree of attenuation.

 

[biertourist]

You should perform a diacetyl force test. Just pull a sample of beer and let it warm up to room temperature over 15-20 minutes and give it a taste paying attention for the diacetyl flavor. -Now put a few inches of hot water in your kitchen sink and warm the beer up further to say 80F and try it again.

(Oxygen + Heat + Diacetyl precursors == diacetyl.)


-Or you can just do the D-rest to be safe.


Adam

 

[BridgewaterBrewer]

I do a diacetyl force test at 140-160F for 10-20min. If you taste butter after heating then there are still diacetyl precursors in the brew and you need a diacetyl rest.

 

[BigFloyd]

Yeast (especially lagers and certain ale strains) will produce the diacetyl precursor alpha acetolactate during fermentation. Yeast can't consume alpha acetolactate.

The d-rest is done to encourage (by a rise in temp) the precursor to go ahead and convert to diacetyl. The yeast cells can then absorb the diacetyl and convert it to compounds that don't have an objectionable flavor.

I like to give my lagers a 3-4 day d-rest at about 62*F (up from 48-50*F) prior to cold crashing.

 

[Jacinthebox]

I would do a D-Rest.
My current Lager was pitched at 68F, and fermented for 12 days at 54F, D-rest for 3 days at 64F, then slowly dropped down to 34F (2F a day) after racking to a secondary.
The SG was about 75% of the OG when I started the D-rest