First time wlp007, stuck fermentation?

[CapitaineHaddoc]

Hi guys,

I brewed 2 times last saturday, an IPA (92% 2row, 1064 OG), and an american stout (90% 2row and munich, 1080 OG). I'm brewing 60l/batch and I use 100l PET fermenters. Both beers were mashed at 147F°.

A week before, I built a healthy 5l starter with 2 vials of really fresh wlp007 (from October 18), I decanted then I split the cake in 2 and I made 2 other 5l starters. I used the YeastCalc application, and both starters were a bit overbuild (around 115% of the needed yeast amount).

I pitched them at 18.5° (65.3F°), and I put the 2 fermenters in my fermentation room at the same temperature (18.5). Sunday morning it was going pretty well, good activity and already krausen.

It was like this for 3 days and it slowly calmed down.

I took a hydrometer sample, the IPA was at 1020 and the stout at 1032. Expected FGs are 1011 and 1020 (I used lactose in the stout).

So I raised the temperature to 20° (68F°), and today I took another hydrometer reading. Both gravity are almost the same.

I never used this strain before. What would you do? Is 18.5° too cold for this strain? Should I swirl the fermenters? Or should I build another starter with another strain (I used 090 with good success many times)?

Thanks in advance, and apologies for my poor english.

Guillaume

 

[kev211]

What was the recipe of the stout? Sounds like it shouldnt have gotten stuck and that temp is perfect for 007

 

[CapitaineHaddoc]

The Stout is a Stone Xocoveza clone, I have the recipe on my laptop.

I have a doubt about the real temperature, the probe is just sticked to the fermenter and isolated. Maybe it's colder inside?

Or could it be just a bad yeast? Starters looked like egg soup, but it seems to be standard with this yeast.

 

[bigdawg86]

That's exactly what my WLP007 starter looked like. I also brewed a stout OG 1.135 and it finished at 1.042 (1.030 panned FG) despite raising the temp to 74 and agitating the yeast. I think it just flocculates like a brick. I ended up with a secondary pitch of a more alcohol tolerant / aggressive yeast.

 

[kev211]

Just went to WL's website. Apparently, that yeast likes the upper end of 60's so it may have been too cool. Also, egg drop is normal for that yeast. Looks gross, but flocculates like a mother. Attenuation is supposed to be 70-80 so that might explain it

 

[flars]

Would like to see the recipes but in the mean time raise the temperature to 22°C and check the SG again in 7 days.

Edit: Patience.

 

[CapitaineHaddoc]

Thanks guys, this is really helpful.

I just set my fermentation chamber to 22°, and I will check the gravity sunday.

If it doesn't work, then I will make a good Wlp090 starter and repitch.

Edit:

And I will post the recipes from my desktop tomorrow. Unfortunately, everything is in metric units.

 

[Gnomebrewer]

Try gently stirring to rouse the yeast (under a blanket of CO2 if you are able to). I've used 007 several times and never had it do this, but have had that issue with 002. English yeasts like to go to bed and not get up again unless you force them. They then have a habit of starting up again when transferred to bottle/keg/secondary, but heating and gently rousing should do the trick.

 

[flars]

Thanks guys, this is really helpful.

I just set my fermentation chamber to 22°, and I will check the gravity sunday.

If it doesn't work, then I will make a good Wlp090 starter and repitch.

Edit:

And I will post the recipes from my desktop tomorrow. Unfortunately, everything is in metric units.

Pitch the starter at high krausen if it is necessary. At high krausen the yeast are very active and less likely to be shocked going into a solution of alcohol.

 

[CapitaineHaddoc]

Hi guys,

I found the issue, just have a look at my fermentation chamber,

Usually I made only 1 batch, so I use the middle part of the chamber. The heat source is in the bottom parts, and there's a few holes in the planch in the middle.

I'm an idiot, as you can see in this picture, the probe is on the bottom fermenter, too close to the heat source, so the temperature in the bottom fermenter was too low, even if I started the fermentation at 18.5°C.

And of course, it was even worse in the top fermenter, temp was under 16°C.

Now I gently stirred the 2 beers and put them back in the chamber @20°C with the probe on the top fermenter. Hope this will be enough (there's only .009 to go with the IPA and .010 with the stout).

And now, as I promised, the recipes:



And again, thanks for your answers, this forum is really helpful.

 

[CKelly]

I've used this yeast a bunch of times in higher gravity beers including a stout and a barleywine and have had issues with it stalling at 1.030ish in both. However, like Gnomebrewer said, just give the yeast a rousing. I sat at 1.030 for about a week expecting it to drop the rest of the way but got no where. After a light rousing I dropped to under 1.020 in a day or two. I think since this one has such high flocculation, it drops before it totally finishes and just needs a gentle nudge as a reminder to finish up.

 

[NewkyBrown]

I've used this yeast a bunch of times in higher gravity beers including a stout and a barleywine and have had issues with it stalling at 1.030ish in both. However, like Gnomebrewer said, just give the yeast a rousing. I sat at 1.030 for about a week expecting it to drop the rest of the way but got no where. After a light rousing I dropped to under 1.020 in a day or two. I think since this one has such high flocculation, it drops before it totally finishes and just needs a gentle nudge as a reminder to finish up.

Just read this post and have the same issue with 007. My stout is a few points off after two weeks. By rousing, do you mean rocking the fermenter or something more aggressive?
Is it ok to stir the yeast with something sanitized? I don’t think rocking will budge this yeast cake...

 

[CKelly]

Stirring it will put you at risk of contamination and/or oxidation. I think giving the fermentor a quick swirl should do the trick, especially if you're only a few points off. Up to you