Weak fermentation from WLP540 Abbey IV?

[Berkyjay]

I have brewed 2 batches with this platinum strain from White Labs and both have had very weak fermentation. My first brew started at 1.070 and after almost 2 weeks and a vial of fresh yeast is only down to 1.022. The second batch has a higher gravity at 1.092 but is showing the same signs as it is only down to 1.038 after a week of fermentation. What is even more frustrating is that my mash temp for both of these was 150F and they bothy used 2lbs of sugar, so they should be ultra-fermentable. Has anyone else used this yeast recently? If so, what has been your experience with it?

[brewinhard]

Those are both high gravity batches and fresh vial or not, a starter should be made to make your fermentation more successful. Did you aerate your wort before pitching?

[MrGaryFish]

I'm planning on using this in a Dubbel/Dark Strong this weekend, and made a 4L starter with yeast nutrient and pitched 2 vials of this, so I think that I should be good. The question I have is, how old is your yeast? This yeast was released new this month as one of the platinum strains, so maybe what you used was expired? It was last out Mar-Apr of last year.

[Berkyjay]

Oh yeah, made a 1L starter for the first batch. I then top cropped some yeast after 2 days of fermentation. I used the top crop yeast to make another 1L starter for the higher gravity second batch. The yeast I got was fresh from the brew store which came fresh from White Labs....I bugged them to get the new platinum strain as soon as it was released. I also aerated both batches with a pump and diffusion stone for an hour and a half. Ever since I nailed down my mash schedule and got my temp control unit set up, every one of my Belgians has fermented out within 3 days (1.015 or below). I did everything exactly the same on these two which is why I am suspect of the strain. MrGaryFish, please let me know how your fermentation goes. 4L is a HUGE amount of starting liquid, are you brewing a 10g batch?

[uncle_bad_touches]

I've had similar experience with WLP540 - it pooped out around 70% attenuation. I've had much better results with the Wyeast equivalent of this yeast - Belgian Ale 2 I believe. It's still not as attenuative as say WLP530, but with low mash temp and lots of sugar you can get into the 80's.

[Berkyjay]

I've had similar experience with WLP540 - it pooped out around 70% attenuation. I've had much better results with the Wyeast equivalent of this yeast - Belgian Ale 2 I believe. It's still not as attenuative as say WLP530, but with low mash temp and lots of sugar you can get into the 80's.

I love Wyeasts 1762, I've made my best Belgians with that. But I heard that this White Labs strain is a Rochfort strain as well. I have never had any issues with the 1762. I consistently use 2lbs of sugar and mash in the 145-150 range with plenty of aeration.