Rousing needed with Wibbler brewery yeast?

[Simonh82]

This is a question possibly for @Kyle_T or anyone else very familiar with the Wibbler/Ridley yeast strain. I've used it successfully in quite a few brews now and really love the flavour it gives to my beer. I'd consider it my house strain now. One issue I have with it is that it often seems to stall slightly after an incredibly vigorous initial fermentation. For instance I've had several brews stick around 1.015 even with modest starting gravity. In these situations I've stirred the huge krausen back in and it kicked off again, finishing the job.

Is this a characteristic of the yeast? Do Wibbler do anything to avoid this, or is it just me? It seems to me that all the yeast floats up to the surface and get stuck in the krausen. It then isn't available to ferment the beer effectively until its stirred back in.

I've got a brew on at the moment and it has taken off like a rocket. Last night it blew off the air lock, despite the fact I upgraded to a 30L fermentor. After I cleaned up the mess I put on the air lock again and the bubbling has slowed right down. I'm worried it is about to do it's usual trick.

I don't want to mess with it unnecessarily but if a quick stir to get the yeast back in to the beer would help, I will do so.

[sbond10]

Sure someone said start cool and ramp up to normal ferment temps ?

[Kyle_T]

Can't say I've ever had an issue with it, I get a consistent 76% attenuation on a standard mash but it will go higher with a lower mash temperature, I often find if fermented at 18°C it tends to struggle to reach full attenuation but at 21°C it performs flawlessly.

Pitching live from the brewery (as I'm always there) the pitching rate will be higher and there may be your problem, if top cropping allow it to warm up and add wort straight after the chilling has finished and allow it some time to acclimatise.

[joe1002]

Can't say I have ever experienced it stalling either but I too pitch it fresh from the brewery and ferment at 20-21c. What are your OG's and fermentation temps?

[Simonh82]

OGs have generally been in the 1.040-1.048 region. My current brew is 10.45. I normally mash at 65°C and do usually reach 76% attenuation too but this time I mashed at 67°C as I wanted a bit more body. I normally ferment at 18-19°C then raise to 21-22°C after a few days.

I always pitch a healthy amount but sometimes the starter will have been built up from yeast that has been sat in my fridge for a while. I store the yeast under beer and the starters always seem healthy.

I'm going to bump the temp up to 21°C and see if it makes a difference. It's only been fermenting for two days which is sooner than I'd normally raise the temp so we'll see if it makes a difference.

[McMullan]

Did you oxygenate the wort? Some yeast strains require a good gentle stir occasionally for the first day or two. As suggested, 'over pitching' a tad does the trick with early dropping strains. Give it at least 2 weeks and check where it is.

[Dennis King]

Only ever used the Crouch vale yeast left it totally alone and it still tried to escape the fermenter.