Stuck or Complete?

[jtsimon]

Long time viewer first time post.

I recently brewed a Oktoberfest recipe using WLP820. See malt bill below. On brew day I pitch a 1 gallon starter at 53F. Fermentation started after about 12 hours and chugged along for about 12 day before krausen fell. Fermentation temp was at 53F. After that I gave it a long (life got in the way) diacetyl rest at 63-64F for 14 days. I took a gravity reading and was at 1.024. I probably made the mistake of thinking it would drop the remaining points getting to lagering temperatures so I decided to transfer to the keg. I also decided to give it another week at 53F before dropping temp.

So my current problem. I began dropping temperature and got to about 40 degrees before deciding to give it another taste. Taste was good but it finished off sweet, too sweet. Best I can describe is not carmely oktoberfest sweet but unfermented wort sweet. I took a gravity reading and am at 1.021. So my question is based on malt bill is this about as low as I can go? Or did I sabotage my yeast by transfering too early? I would like to dry this beer out a little and am debating pitching a high krausen starter with the same yeast and seeing what happens. I feel like a couple gravity points may fix the problem. Currently, I upped the temperature back to 53F and gave it a little swirl in the keg to try a rouse what remaining yeast there are.

I appreciate your feedback.

5 gallon
1.059 OG 23 IBUs

4lb - Pilsner
4lb - Munich -20l
2lb - Vienna
8oz - Cara-Pils
6oz - Caramunich

 

[Benedetto]

Sounds like something that happened to me when I was making a lager once.

What was your mash temperature?

 

[jtsimon]

Mash temp was at 152F.

 

[Benedetto]

Yeah, that's sufficiently low.

If it were still in the carboy I'd say let it warm up and swirl it. I don't keg my beer, but I presume that would have the same effect, just with more trub on the bottom you'd need to deal with.

 

[dmtaylor]

I recently brewed a Oktoberfest recipe using WLP820.

I'm sorry. That's your one error right there: WLP820 is a complete crap yeast that should not be sold. Any other lager yeast in the universe is 50 times better. It's a very poor attenuator. Fermentation is complete. You could try adding a big yeast starter of a different yeast, or just live with the high gravity of this batch. The WLP820 will not be going any further for you on its own.

 

[jtsimon]

I'm sorry. That's your one error right there: WLP820 is a complete crap yeast that should not be sold. Any other lager yeast in the universe is 50 times better. It's a very poor attenuator. Fermentation is complete. You could try adding a big yeast starter of a different yeast, or just live with the high gravity of this batch. The WLP820 will not be going any further for you on its own.

I did a little more reading on this yeast and attenuation is 65-73%. I am sitting right at the low end. So I think you're right and it probably done. But since I've already got it warmed back up, I'll give a week to see if it moves at all. Otherwise looks like I'll be living with higher FG. I would hate to risk oxidation by pitching another yeast.

Thanks for the input.

 

[p_p]

Cannot comment on your beer. But may be able to offer some advice.

I always take a wort sample for reading gravity and pH. Then I put this sample back in the stir plate and force ferment it warm so I know where the beer will finish. If my fermentation ever gets stuck (touch wood), I will know.

 

[Aristotelian]

I did a little more reading on this yeast and attenuation is 65-73%. I am sitting right at the low end. So I think you're right and it probably done. But since I've already got it warmed back up, I'll give a week to see if it moves at all. Otherwise looks like I'll be living with higher FG. I would hate to risk oxidation by pitching another yeast.

Thanks for the input.

How does pitching another yeast risk oxidation? If you are worried about splashing you could funnel a small liquid starter through tubing, or just use a dry yeast.

I hate cloying beers personally. I would rather take the oxidation risk than go with a known bad beer.

 

[dmtaylor]

I don't see any risk of oxidation. If you want more attenuation, add a ton more yeast. If you're lucky enough to have a yeast cake from a second batch, go ahead and add the cake. At this point, it doesn't even much matter what yeast you use. Any relatively clean yeast could help, and the character of the original lager yeast will remain predominant.

 

[headfullahops]

If you're pitching more yeast, any oxygen you introduce into the beer will be taken up by the yeast before it gets busy fermenting. I know people who re-oxygenate big beers (barley wine, etc.) mid-fermentation to aid in attenuation. I think the attenuation stat is possibly the most important one attached to yeast with the exception of of style profile.

 

[joegbeer]

Just to give you another point of reference using WLP820.

I mashed at 152 for an original gravity of 1.054. I cooled the wort to 53 degrees and pitched a decanted 5 liter starter. Fermented for 7 days. When the kraussen just barely started to fall, I pulled the carboy and placed it at room temp (basement) 68 degrees for a diacetyl rest. I could see fermentation heat chruning the beer for about 3 days, left it stand for 5 days. Kegged for lagering and the final gravity was 1.016. Beersmith was predicting 1.014, but I was happy with the results.

I'm just wondering in your case if leaving the yeast at the colder fermentation longer cause it to stall out?

 

[pdxal]

Somebody has to ask...
Are you measuring gravity with a refractometer?

 

[jtsimon]

Just an update:

All gravity reading taken with a refractometer, agitate CO2 out of solution, and temperature monitored/corrected.

The good news. It seems as though this yeast is still working away albeit very slowly. Its been roughly 5 days since warming and rousing the yeast. I took a gravity reading today and gravity was at 1.019! The biggest thing I notice in taste is noticeably drier finish...almost there. Beersmith has this recipe calculated at 1.017 gravity so not far off. At this rate I think I'll show a little more patients and see what happens.

 

[jtsimon]

I hate cloying beers personally. I would rather take the oxidation risk than go with a known bad beer.

Oxidized beer or cloying beer = bad beer. Personally, a slightly sweet beer is more drinkable than my one and only dumped beer which was oxidized (dry airlock). I do agree though...in this situation, the risk of a severely oxidized beer is low.

 

[pdxal]

Are you using a refractometer correction? If not, the gravity is lower than you are measuring.