Odd lager fermentation

HomeBrewTalk.com - Beer, Wine, Mead, & Cider Brewing Discussion Community.

Help Support Homebrew Talk:

kiblerjd

Well-Known Member
Joined
Jul 11, 2013
Messages
200
Reaction score
35
Hello everyone. Have brewed a few lagers recently with great success but the most recent one is acting funny so i figured I would reach out.

Brewed a fairly basic pilsner on 2/21. OG 1.059 (got way better efficiency than expected). Used WLP802 from a 2L stir plate starter. Fermentation temperature 54F (glycol cooled fermenter)

The yeast must have been very happy and healthy because I had very active fermentation a few hours after pitching. On day 5 I was already at 1.02 according to my tilt (1.017 by refractometer) which is my typical queue to start the D rest. So i raised temperature to 64F. This is where the issue is. My last few lagers once the temperature was raised it typically went to FG pretty quickly. I'm expecting about 1.012 for this one. Three days at 64F and it has only gone down to 1.019. This seems very strange to me. I'm still getting a few bubbles from the airlock but gravity is not going down. New enough to lagering that i figured I would ask for some advice here.

I can very easily hook CO2 up to the bottom of my fermenter and agitate the yest if needed but not sure if that is the right thing to do. Thanks in advance.
 

VikeMan

It ain't all burritos and strippers, my friend.
Joined
Aug 24, 2010
Messages
3,335
Reaction score
2,293
Three days at 64F and it has only gone down to 1.019. This seems very strange to me.
First, I wouldn't be too worried yet. Is this a 5 gallon batch? If so, many people (including me) would say that a 2L starter for 5 gallons of 1.059 lager is an under pitch, even if that yeast was brand new. Not that it's not likely to finish, but it could be a risk for getting some extra esters and a slow-ish fermentation.

Second, is that 1.019 according to the tilt? If so, I would take a reading with a regular hydrometer.
 
OP
K

kiblerjd

Well-Known Member
Joined
Jul 11, 2013
Messages
200
Reaction score
35
Hello there. Yes it was a 5 gallon batch. My previous batches i was just pitching two packages of yeast but i went with the starter this time to save time and because in theory it would be pitching way more yeast. My last couple batches when i was pitching two packs of yeast, the fermentation was very slow but it was a consistently slow drop from OG to FG at like 1.010. This one took off like a shot then stalled.

And yes it was 1.02 with the tilt and i also sampled with the refractometer which gave me 1.017 (corrected). I rarely trust the tilt other than the trend it gives me. But either way i'm stalled several points above where i should be. I have no problem being patient and waiting it just seems very odd to me.
 
OP
K

kiblerjd

Well-Known Member
Joined
Jul 11, 2013
Messages
200
Reaction score
35
I guess the one other thing i will add here is that for my last lager i used lalbrew diamond lager yeast (temp range of 50-59F), and the one before that was bohemian lager 2124 (temp range of 48-58F). I used the same fermentation temp (54) and d rest temp (64) for all three batches but i'm just now seeing that WLP802 has a temperature range of 50-55F so i was pushing the upper end of that range.

Maybe give it a few more days at 64 then go back down to 52 and agitate the yest a bit? I'm probably worrying about this way to much. If it tastes good and gets me drunk who cares.
 

VikeMan

It ain't all burritos and strippers, my friend.
Joined
Aug 24, 2010
Messages
3,335
Reaction score
2,293
And yes it was 1.02 with the tilt and i also sampled with the refractometer which gave me 1.017 (corrected).
A hydrometer might give you a third number. Refractometers are great, and I use mine all the time, but if in doubt I'll take a hydrometer reading over a refractometer reading every time. Also, you might want to check the calibration of your refractometer if you haven't already.

I used the same fermentation temp (54) and d rest temp (64) for all three batches but i'm just now seeing that WLP802 has a temperature range of 50-55F so i was pushing the upper end of that range.
I've never seen a yeast strain that wasn't perfectly happy to work above its published range. It's fine for yeast health (if not necessarily for beer flavor early in the fermentation). Unless you're getting up near "kill" temps (and you're nowhere near that) the yeast will actually work faster the higher you go.

Maybe give it a few more days at 64 then go back down to 52 and agitate the yest a bit?
Personally, I wouldn't lower the temp at all until you reach terminal gravity.

I'm probably worrying about this way to much.
This is the case with, I dunno, about 95% of these kinds of threads.

Another thought... where is the expectation of an FG of 1.012 coming from? My thinking is...hydrometer could show you are even lower than you think, and the FG expectation might be a bit low, which could further bridge the gap.
 
OP
K

kiblerjd

Well-Known Member
Joined
Jul 11, 2013
Messages
200
Reaction score
35
A hydrometer might give you a third number. Refractometers are great, and I use mine all the time, but if in doubt I'll take a hydrometer reading over a refractometer reading every time. Also, you might want to check the calibration of your refractometer if you haven't already.
Well mother fragger now I feel like a real idiot. I checked the calibration on my refractometer and it was a tiny bit off. Took another reading and I’m at 1.011. Sorry for wasting your time. Sometime it’s easy to forget that the simplest solution is usually the correct one.

on a separate note I might toss this tilt. It has never given me reading that we’re even close.
 

Snuffy

Airlock Sniffer
Joined
Nov 5, 2019
Messages
557
Reaction score
629
The Tilt is probably not faulty - it just gets yeast growing on top of it, which throws its balance off and makes it read a bit high.
 
OP
K

kiblerjd

Well-Known Member
Joined
Jul 11, 2013
Messages
200
Reaction score
35
The Tilt is probably not faulty - it just gets yeast growing on top of it, which throws its balance off and makes it read a bit high.
right..... which therefore makes it completely useless
 

VikeMan

It ain't all burritos and strippers, my friend.
Joined
Aug 24, 2010
Messages
3,335
Reaction score
2,293
right..... which therefore makes it completely useless
I don't own a tilt, but I've read enough user praise and user misery to know that while they are not always reliable (quantitatively) for gravity readings, they are pretty good at letting you know when the FG has stopped moving. If I owned one, I'd use it for that, and take a single hydrometer reading right before kegging.

FWIW, I usually use a refractometer for in-process sampling, which is easy because a have a sample valve. I don't pay much attention to the number itself, but rather whether the number has stabilized.
 

iamninjabob

Unapologetic Hophead
Joined
Aug 14, 2020
Messages
43
Reaction score
38
Location
Atlanta
I love my tilt, and would buy another one in a heartbeat if mine broke or something. It's far from perfect, but it's still the best way for me to get a temp and gravity reading without opening the fermenter. Just like Vike said it's best for knowing once gravity has stopped changing, so I always know ASAP when it's time to get it packaged. I take a refractometer/hydrometer reading at packaging, and the Tilt is usually pretty spot on unless I'm using a yeast that makes a lot of krausen (Looking at you Verdant IPA).
 
Top