Wanted to see if anyone has any advice on this one - I’m doing a German Pils and after 27 days in the fermenter, it seems to have finished out at 1014 from an SG of 1050. Was trying to get it down to at least 1012 (75% attentuation) but it doesn’t seem to want to get there. Started fermenting at 50 deg for 2 weeks (1020 at that point) and then ramped it up to 66 to hopefully finish it out. The last 1014 sample I pulled is a rounder mouthfeel than I’m looking for but I know that will change with carbonation. Thanks in advance for any thoughts!
From my experiences, trying to fix an unattenuation problem results in not-so-good results. Since you’re only .002 from expected, I’d leave it alone, enjoy the beer, and take detailed notes. Next time, try a slightly more attenuative yeast, lower the mash temp a couple of degrees, or something else to reach your objective.
Attenuation is mostly about wort composition. However you mashed this, the wort simply had more unfermentables than you intended. But even the best palate in the world is not going to be able to tell the difference between 1.014 and 1.012 (anyone who claims otherwise…that’s just confirmation bias).
If you’re hell bent on getting those last couple of points of attenuation, the only real option is to add glucoamylase (e.g. ultra ferm). Monitor the gravity very closely and cold crash to arrest further yeast activity as soon as you hit your target–otherwise attenuation will continue, and you probably don’t want a 1.000 pilsner.
Or…just enjoy the beer, and make adjustments on the next batch.
Thanks for the advice and the thoughts on the wort composition. My first run at this recipe which was pretty straightforward and should have been pretty highly attenuative. Scratching my head on that one a bit. 10# pilsner & .25# acid, step mash 130 for 20 min, 148 for 45 min, and mashout at 167. Could oxygenation potentially be a culprit as well? I haven’t used an O2 stone to oxygenate, recently have just been agitating the wort via 2 step BK drain to bucket and bucket drain to carboy. Thinking I should probably change that process up.
I wasn’t 100% happy with the bitterness and depth (too much) of my last pilsner, so I watered it down a little bit with distilled, then enjoyed it better. Just another valid option to consider.
Otherwise I really wouldn’t try to change it, you could ruin it. Just do what you can to try to enjoy what you do have in front of you.
Great suggestion, may play around with that in a sample to see. The beer is actually pretty darn good as it is, I’m just trying to achieve that elusive pils perfection as well 
You didn’t mention which Pils malt was used. There are a lot of options, and there are differences. You could consider trying a different one next time.
Went with the good ol’ traditional Weyermann on this one.
In my experience an O2 stone is unnecessary.
2 weeks at 50F probably finished it off before the temperature ramp, but I doubt that would hurt it much (maybe long term storage would be impacted by that long of a primary, but maybe not). In the end, your yeast may not have been able to deal with the wort composition/cold lagering combination - perhaps try a little warmer fermentation and/or a bigger pitch. But first get this one carbonated and let us know if that changes your perception.
On the other hand, the quality of my beers immediately jumped to the next level when I started oxygenating via O2 stone. It made a very noticeable difference. Pretty much all the homebrewers I know have made the same observation.
If it works for you, cool, but never underestimate the power of confirmation bias. Just like aerating before pitching dry yeast…
I’m glad it did something for you. It didn’t for me.
Tell us about your pitch - how many packs, how old, what size starter (if any), SNS/stir plate/other, etc. That’s one variable that I haven’t seen addressed yet, and it could have a significant impact on yeast performance.
Inadequate aeration coupled with allowing a starter to ferment out before pitching can definitely lead to attenuation problems. The reason why I stated that an SNS starter needs to be pitched at high krausen is because it reduces dissolved O2 demand. An SNS starter when pitched into a well-aerated wort at high krausen will perform as well as a much larger starter that is allowed to ferment out because it can do more with the dissolved O2 in the wort.
Great question on the starter. 1L stir plate w/ 3.4oz DME started 24hr before pitching. Let it settle, decanted it off and pitched. Wort was aerated and ready to go at 66 deg along with the starter at the same temp so that’s when I pitched and then dropped by 4 deg/day to get to ferm temp of 50. Had read that this approach was fine but later read a different perspective that you should never do that for best results with lagers. Different opinions in brewing? Who knew?! ;-) Love any other thoughts on this, but next crack at it I’m planning on chilling wort & starter to 50 deg before pitching and see how that works. That in and of itself is an argument for the O2 stone - seems like it will be easier and more reliable to aerate at that point.
Please do me a favor an read this blog entry: Shaken, not Stirred: The Stir Plate Myth Buster | Experimental Brewing I guarantee that you will put your stir plate on eBay or at least park it permanently if you give SNS a shot.
A 1 liter starter seems a bit small for a 1.050 lager, especially if you fermented it out and crashed it. 1L would probably be fine for a SNS starter at high krausen, but I’d go up to 2 liters for a traditional stirplate starter.
Also, I know that this opposes common brewing lore, but I’ve never noticed an issue if my yeast or starter are a different temperature than my wort. I’d just add the starter right to the chilled/aerated wort and let it go.
Great post, thanks for sharing. Will now try the SNS method, but the downside is that the stir plate looks cooler. Makes me feel scientific 
Thanks Eric, and good to know on the temp management of the yeast/starter.