Just racked a Patsbier to a keg and if I calculated right I got 90% attenuation wth WL530 around .004 from .061. Of course I only used a hydrometer but still. The average is posted at 75% or so. Mashed at 149 and added 1/2 lb sugar.
I’ve seen high attenuation with this yeast, so I can totally believe it. Actually what I’ve found is that this yeast takes about a month to hit final gravity, when fermented at the usual temperatures in the mid-60s Fahrenheit. In the past this has caused problems when I thought fermentation was finished, when gravity might have been in the 1.010s, but then the bottles were gushers because fermentation continued so much in the bottles. In your case, it sure seems like fermentation is bottomed out. Did you, by chance, ferment for several weeks and/or at higher temperatures in the 70s? If that’s the case then I definitely believe your results.
All these finicky characteristics aside, WLP530 continues to be my all-time favorite Belgian yeast. It’s just very “Belgiany”, has all the right flavors. I don’t really want to use any other yeast for my Belgians, except for the Belle Saison for all my saisons which is another great but finicky yeast. These yeasts like a long time to finish, even at elevated temperatures. And that’s fine. Patience is rewarded.
I’ve had to wait on this yeast before but this one went fast. 3 1/2 weeks. First week mid 60 second week mid 70 then lowered it basement temp around 68 to finish. I did pitch slurry that I activated and added nutrient so no lag time.
Attenuation rating is simply a way of comparing one strain to another and may not be indicative of the attenuation you’ll get. That is much more dependent on wort composition. You made a very fermentable wort so you got higher attenuation.
I’ve gotten 80% before but had to wait. Just surprised is all. I was going to retire the yeast since I’ve been repitching it for a year but now I think I’ll keep it going.
The sugar and mash temp definitely helped! I just got 80% attenuation on an Ipa using the burton ale yeast.
I actually split that mash into 2 pots one became a Pilsner with 34/70 and that one stopped at .010. So I guess the sugar was the difference. No sugar in the pils obviously.
