Adding fermentables to trigger a D-rest for lager after primary, will it work?

[ghpeel]

I've done a couple lagers, and my last one (a Bo Pils) was a butter bomb, my first such tragedy. I raised my temp controller up from 52F to around 62-64F when the beer hit 1.021, and it finished later at 1.010, but nonetheless some diacytl was still present I guess, cause it got buttery in the keg, and got worse over time.

I was wondering if the following would work:

Instead of trying to target when you are at 80% (~1.020 or so), would it be acceptable to ferment out the lager completely at the same temp, then raise it to 65F, then add another couple points of fermentables (DME/LME, honey, dextrose, etc), and ferment that at 65F?

I detest having to "hover" around any beer, and taking daily samples to find when my lagers are 80% done is annoying, and clearly I didn't do it correctly on that last one anyway. Would the above method be a more "fool proof" way of fermenting 15-20% of your fermentables at the D-rest temps?

 

[Yooper]

I don't think so. You want the yeast to digest diacetyl, not more fermentables.

It sounds like the diacetyl rest wasn't long enough.

Some yeast strains produce more diacetyl than others, so the first line of defense would be to chose a lower diacetyl-producing strain. Also, pitch a HUGE starter at 45 degrees and then allow the temperature to raise up to about 48-50 for fermentation, raising up for the diacetyl rest when the beer is about 75% of the way to FG. That should fix it.

 

[ghpeel]

Yooper, if the D-rest is done so the yeast can (a) finish the final 20% of fermentables, and (b) clean up the diacytl in the process, can you elaborate on why you don't think my plan would work? I'm not quite following you on why the yeast would behave differently.

Also, how long do you do a D-rest for, and is 65F sufficient? I wonder if my beer didn't warm up to 65F quick enough, so the majority of the fermentation actually occurred at 50F.

Finally, fwiw, for that diacytl-bomb, I pitched it with slurry of a freshly racked pumpkin lager which had been fermented with 2 packets of 34/70. Do you do anything different if you are pitching on a cake or from slurry as opposed to a fresh batch of yeast?

Thanks for your brew-wisdom here, it is much appreciated

 

[CharlosCarlies]

I've been recently reading some old brewing texts on lagers, and maybe I'm misapplying this....but what about Krausening w/ about 10-15% of the volume? (assuming this is possible w/ your equipment setup)

 

[CharlosCarlies]

Thinking further, maybe you could just build a small starter w/ fresh yeast and pitch it at high krausen?

Edit:

it got buttery in the keg, and got worse over time.

Have you ruled out a bacterial infection? They can throw diacetyl as well.

 

[ghpeel]

Krausening is just adding fresh wort to lagered beer with a dose of fresh yeast, correct? If so, that's SORTA what I'm talking about. I wouldn't add any yeast, since the yeast that just got done eating the sugars in the primary would still be active and in suspension.