Bohemian Lager stalled at 1.021?

[skarz]

Last Saturday I brewed a German Pilsner, which I chilled to room temperature (67°F) and pitched my 1200ml starter of Wyeast Bohemian Lager which was also room temperature. OG was 1.043. After pitching the yeast I transferred the carboy to my Inkbird controlled fermenter and lowered the temp to 50°F. Lag time was about 24 hours. Rather than bore you to death with all the details, I'll present the data from my Tilt. I have only swirled the fermenter once and that was when fermentation stalled around 1.030 for 12 hours. After that it dropped to 1.021 and then went back up after another gentle swirl. I'm kind of at a loss as what to do now.

 

[AlexKay]

When my Tilt SG trace goes up and down like that, it usually means krausen has gotten on the device ... which is the situation where you can’t trust the absolute reading. It’s really the relative readings that are valuable anyway — when you see SG go flat for a week, you know it’s done, at which point you measure the FG with something else.

That said, it doesn’t look like you’ve been stuck for very long. I’d give it (much) more time.

 

[skarz]

When my Tilt SG trace goes up and down like that, it usually means krausen has gotten on the device ... which is the situation where you can’t trust the absolute reading. It’s really the relative readings that are valuable anyway — when you see SG go flat for a week, you know it’s done, at which point you measure the FG with something else.

That said, it doesn’t look like you’ve been stuck for very long. I’d give it (much) more time.

Interesting. I really hope it's not done, otherwise I'll have a 2.5%ABV on tap. Do you think I should raise the temp and give it a swirl? Still has a pretty thick krausen!

 

[VikeMan]

Interesting. I really hope it's not done, otherwise I'll have a 2.5%ABV on tap. Do you think I should raise the temp and give it a swirl? Still has a pretty thick krausen!

You're on what, day 5? Too early to even think about doing anything special IMO. Also, is this a 5 gallon batch? If so, IMO you underpitched a bit for a 1.043 lager, which I would expect to slow things down. My recommendation would be patience.

 

[jdauria]

Agree with Vikeman, you underpitched slightly if it's a 5 gallon batch, maybe more than slightly depending on age of yeast. I have found that with a properly pitched lager takes at least 6 days, maybe even a few more if held at 50 the whole time. I would start bumping temp up for a diacetyl rest and maybe the warmer temp will finish it off.

For reference, I have a Czech Dark lager fermenting that I am kind of rushing a little. I brewed it last Saturday, pitched Sunday morning at 49F and 1.054 OG and then it rise to 52 for 3 days, then 54 for 3, as of last night it was 80% of the way to estimated FG, so I bumped to 60 and this morning it's at 1.015 (estimated FG was 1.016). So 5 days is doable, but at warmer temps. Normally though, most of my lagers I ferment at 48-50 and pitch a yeast starter that is at least 1.5 billion cells/ml/degree plato using Brewers Friend's yeast calculator and then are usually at FG in 6-7 days.

 

[madscientist451]

There's a quick lager method where you ferment cold until its about 50% done then finish at room temperature.
If you're in a hurry, try it out.
I've done it before and the beer is fine, but if you want to wait and also cold lager for a few months the beer might be even better.
You could finish up this batch quickly, have something to drink in a week and then re-brew and use the yeast cake on the next batch and let that ferment all the way at the lower temperature.