Pilsener only at 1.02 after 4 weeks

[timsch]

I don't brew anything that requires lagering for the most part, but am brewing a Pilsener now. I followed a typical Bohemian Pilsener recipe and used WLP800 with about a 2L starter. Fermentation ~50F lasted about 2 weeks, at which point I lowered the temperature to 38F for another 2 weeks.

I've been spoiled by all my typical brews, usually IPAs, finishing fine, so didn't check on the gravity before transferring to my Corny this morning. A check at that time showed the gravity to be ~1.020.

At what point during the fermentation is FG usually achieved during this process for a lager/pilsener? How much additional drop happens during the lower temperature stage?

What can I expect from it in the Corny at 40F serving temp? If I kept the pressure off of it in the keg for a few more weeks, would that benefit anything?

 

[lumpher]

No diacetyl rest?

 

[GoeHaarden]

How did you check gravity? Hydrometer or Refractometer? If hydrometer, what temp was your sample?

My lagers typical take abt 1 week or less with a bump to ~65F for diacetyl rest near the end of fermentation. The rest is all conditioning. Not sure keeping it 40F is going to do anything for you

 

[timsch]

No, no diacetyl rest. I failed there. I just referenced Brewing Classic Styles as well as Designing Great Beers and neither one mentioned it, so it slipped my mind. The devil's in the details, as is the great beer, which is why I continue to miss the mark.

I checked with a hydrometer @ 80F.

 

[Deadalus]

50F is at the bottom of the recommended fermentation temp for that yeast. If I remember correctly the last time I used it I tried that temperature and it was slow and I had to bump it up a few degrees. I tried 50F a few times with lagers and had slower starts but it may have been before I started oxygenating. This is my Schwarzbier, (WLP820 however) that is going on 9 days. It was at 51F for about 5 days then I bumped it up a degree and the other day I let it rise to 55F but it has slowed down and not quite done I'd say. What was your original gravity? MIne was 1.050.

I very much doubt it will do anything at 40F. You've racked it off the yeast. That lower temperature you had it at, 38F, that just clears it up. I pretty much never used to do a diacetyl rest, but I did always use 21 days for letting my lagers ferment in the past. This is my first one with the Tilt in so I am reevaluating. There was one time I did have diacetyl problem but I think it was WLP830 although it was a pilsner. It was already in the keg like yours. I let it warm up and left it for about 2+ weeks. I think the first time I checked it was still wasn't cleared out but I do recall it eventually did and was good after that. A recommendation if you can't get the diacetyl out (if present) is to pitch a small volume of wort in with a clean fermenting yeast, WLP001 may have been the one recommended. If your gravity doesn't drop it'll probably be a little sweet.

 

[timsch]

My OG was 1.052 or -54. FG is listed in the recipe could be up to 1.017, so I'm not that far off. If I'd let it go another week at 50F, or raised it a bit, I'd probably be where I should have been. I'll just live with any extra sweetness this time, and do better next time.

 

[dmtaylor]

WLP800 is actually an "ale" yeast, Sacch. cerevisiae. It might be helpful to warm it up to mid 60s F for a week. Couldn't hurt.

 

[Beermeister32]

Agree, warm it up for your D-rest, mid 60’s F, hold for a week.

 

[Beermeister32]

Also mentions 4-6 weeks in Primary

 

[timsch]

Looks like I need to start reading the particular yeast info. Shame on me.

 

[Bobby_M]

50F for the first week, then 60F until it's done.

 

[Bobby_M]

WLP800 is actually an "ale" yeast, Sacch. cerevisiae. It might be helpful to warm it up to mid 60s F for a week. Couldn't hurt.

Source?

 

[dmtaylor]

Source?

http://beer.suregork.com/?p=4030
http://beer.suregork.com/wp-content/uploads/2019/10/Brewing_yeast_tree_Oct_2019.pdf

 

[Andre3000]

This should well be done at 50F for 2 weeks. What can you tell us about your mashing process?

 

[timsch]

Electric BIAB. ~152F for 1 hour, temperature monitored with multiple sensors. Grains ground immediately before mashing.

Fermentation temperature controlled in a converted chest freezer.

 

[jdauria]

Well as others have said, after a week your fermenting temps should go up for a D-rest, not down to lager temps. Lager yeast needs time to clean up after itself, diacetyl, sulfur, etc. and needs a couple weeks before cold crashing. But also, what was your OG? Was that 1 pack of yeast in a 2 liter starter? Depending on your OG and the age of the yeast, it's possible you also did not pitch enough yeast.

 

[Andre3000]

Electric BIAB. ~152F for 1 hour, temperature monitored with multiple sensors. Grains ground immediately before mashing.

Fermentation temperature controlled in a converted chest freezer.

Are you recirculating?

 

[timsch]

No, no recirculation. Just a more primitive setup with a converted Sanke half keg wrapped in a quilt. Temperature drops maybe 3 degrees over the course of the hour. Fairly fin grind, so it's likely done converting after half that time.

It was a single pack of yeast, but was fairly fresh, maybe a month or 2 at most after packaging @ WL. I've made starters from less yeast than that (30ml frozen cultures).

 

[Andre3000]

No, no recirculation. Just a more primitive setup with a converted Sanke half keg wrapped in a quilt. Temperature drops maybe 3 degrees over the course of the hour. Fairly fin grind, so it's likely done converting after half that time.

It was a single pack of yeast, but was fairly fresh, maybe a month or 2 at most after packaging @ WL. I've made starters from less yeast than that (30ml frozen cultures).

Ok.

1.052 to 1.020 is only 60% attenuation. So something has definitely gone wrong. Look at your mash or yeast health.

Most of my underattenuation issues were traced back to mash. I was recirculating with my BIAB and it caused all kinds of problems with low attenuation which is why I ask. Doughballs can cause underattenuation too. Make sure your mash is super uniform after doughing in. I started milling coarse and accepted a small efficiency loss to as a trade off to eliminating the need to put in a large effort breaking up dough balls and stirring like mad. I still get 80% efficiency with no pump.

You said EBIAB, make sure if you aren't circulating, that you aren't heating at all. The temp drop will from not heating will cause way less issues than trying to heat an uncirculated mash in my opinion. You could unknowingly be denaturing the beta-amylase if there are hot spots and stratification which is very likely if you're heating a BIAB with no pump.

On the yeast side of things, one can get away with cutting corners with ales but with lagers need every advantage to turn out well. Was your starter vigorous? Did you use a yeast nutrient? Are you oxygenating right at pitch?

 

[timsch]

I had multiple issues this brew session that serve as a kick in the a$$; one was learning that I've been oxygenating too early before pitching the yeast.

I used a stir plate and a gallon jar and had a krausen overflow, so vigor was not lacking.

I've got a pretty good process where I pour my ground grains slowly into the bag-lined kettle while stirring; I wind up with a very manageable doughball issue that way.

I almost never heat during the mash, and did not this time. Whenever I do, I lift the bag several inches above the element and heat for the briefest time to raise the temp @ the sensor maybe 5 degrees at most. Heat is usually on for less than 30 seconds, probably closer to 20.

I did not use yeast nutrient as I've not needed it for ales. I understand that this does not necessarily mean it's OK for lagers. I'll consider that in the future.

My "e" part of the BIAB is limited to temperature/boil control. I'm fancy in no other way, being the cheap bastard that I am....

 

[cactusgarrett]

Doesn't help you now, but in the future let the beer tell you when to move things along in-process (d-rest, package, etc.). Even in this thread I'm seeing a lot of "do this after X weeks/days, hold for a week, etc." before moving to the next step. Anything done should never be based on time, but only on how the beer is progressing (specifically what the gravity is telling you).

 

[Bobby_M]

Doesn't help you now, but in the future let the beer tell you when to move things along in-process (d-rest, package, etc.). Even in this thread I'm seeing a lot of "do this after X weeks/days, hold for a week, etc." before moving to the next step. Anything done should never be based on time, but only on how the beer is progressing (specifically what the gravity is telling you).

While technically true, rules of thumb are better than no rules at all or ignoring the basic concepts. If the rule of thumb fails, it would be indicative of other problems like poor yeast health or severe underpitching. In my example, a week of fermenting at 50F should be a reasonable place to ramp up. If it's only half attenuated at that point, it was probably way underpitched. IF a brewer has the ability to pull samples daily without opening up the fermenter to tons of oxygen, by all means they should do it the technical way.

Either way, point taken.

 

[cactusgarrett]

rules of thumb are better than no rules at all or ignoring the basic concepts.

Very true. I wasn't trying to call anyone out, just that I wish our hobby's recipe instructions were overhauled to add clarity that any timelines included should also include some reasoning and the modifiers "at least X long" and to measure and err on the side of too long as opposed to not long enough.

It pains me when I see new brewers post "I followed the instructions to the letter and now [insert problem here]" when that could possibly be avoided with some additional recipe clarifications.

 

[pocketmon]

Have you done any Fast Ferment Test ?
You will know at least the fermentability of your wort.

 

[smata67]

Your primary mistake was not measuring the FG after two weeks, you went ahead and cold crashed without knowing that fermentation was not yet complete. You want a pilsner as dry as you can get it, in the low teens at least. If you would have measured FG, you would have found it to be 1.020 and given it more time. No matter, at this point the thing to do is raise the temperature to get that fermentation going again, maybe 60F, and let it sit for awhile. Hell, I'd even go to 70F, but I'm a rascal. How long? Well, again, do it based on FG MEASUREMENT, not TIME. But if after 2 weeks you are still stuck stuck at 1.020, I'd go ahead and bottle/keg, nothing more is going to happen. Well, you can almost certainly get it down further, but probably not worth the trouble and could end up oxidizing the beer, not something you can tolerate on a lighter beer. Either way, I strongly suspect it will be drinkable even at 1.020 FG.