Foamless Fermentation with WLP005

[Middo]

I brewed a bitter last Saturday using White Labs WLP005, popped it in the water bath and set the heater to around 19C. It started out well with visible activity after 12 hours and a good solid head of foam after 24. However, when I got home from work on Monday the foam had completely disappeared and the surface was fizzing away like crazy. The only other time I've seen this was when I used a heating belt and it heated the beer to around 27C, but I checked the temperature on Monday and it was only 21C. The maximum recommended fermentation temperature for this yeast is 20C so I doubt 1 degree would make much of a difference, so I'm pretty sure it's not the temperature that's the cause. Any ideas?

[smuggles]

I think that's just what this yeast does. I used it for the first time myself a couple of weeks ago, and like you the yeast dropped after 24hrs. I didn't check the gravity for another few days, but by then it had reached its target FG, so it all worked fine.

Just checked whitelabs site and they say this:

This is normal behavior for the British yeast. You don't see that much activity because it doesn't rise to the top at all. It ferments from the bottom, unusual for ale yeast but becoming more common as many UK ale brewers have switched to conical fermentors. You should still be getting good CO2 generation, however, and that should be strong. Sometimes people rack off after a day or so, which in the case of this yeast, it would leave it all behind. It's best to leave it and not rack the beer until approximately 24 hours post terminal gravity, at the earliest. If you didn't rack, it would be very unusual for fermentation to not be complete with 70 F constant temp and good aeration.

[seymour]

I think that's just what this yeast does...

Correct. WLP005 is likely the Ringwood Brewery strain via historic Pripps Porter in Sweden, which is well-known for excellent flavour characteristics but high oxygen requirements and benefits from periodic rousing during primary fermentation.

[Middo]

Thanks for the replies; I probably should have checked the White Labs website before posting eh?

Anyway, I roused it over the weekend and it's now reached 72% attenuation so all looks good.

[seymour]

... it's now reached 72% attenuation so all looks good.

That's good, though it may not be finished. This yeast typically attenuates at least 75-80%. Of course, much depends on the complexity and fermentability of your wort. I'd just keep checking your Final Gravity for a couple days before kegging/bottling to be sure.

[Middo]

Really? The White Labs website says 67-74%? The OG was 1.047 with quite a complex grain bill: pale ale malt, wheat malt, crystal rye, flaked corn, flaked rice and toasted oats (I was basically using up a load of grains that had passed their best-before dates). It's been at 1.013 since my last post so it's now in the barrel.

[seymour]

Right you are. I see that too on their website. I don't know why my records said that, but I've updated them. I'm sure your fermentation is finished.