Attenuation of White Labs WP029 Kolsch yeast at 85%

[indianajns]

Just checked my White labs poster and it shows the WLP029 Kolsch yeast attenuation at 72 -78%. My OG = 1.047 and the FG was all the way down to 1.007. (I calibrated my hydrometer and performed the reading at 59 F for FG) This is an apparent attenuation of 85%. My question is should I be worried that my attenuation is 7% above the high end of the White labs chart? What could cause this? I'm assuming maybe bacteria or perhaps an overpitch? I've tasted this very young beer (Blonde Ale) and right now it tastes fantastic so I'm guessing no bacteria but don't know enough to be sure. Can an overpitch cause a higher attenuation? Any thoughts would be appreciated.

 

[masonsjax]

Could have been a misreading, or maybe bubbles or trub threw off the reading. If it was all grain, maybe you mashed low. If you had simple sugars in the recipe like honey or cane sugar it could attenuate more than predicted too.

 

[IL1kebeer]

Those attenuation numbers aren't set in stone. I get 80% from that yeast when I use it in my American Wheat even though I mash pretty high. I'd imagine a Kolsch grist would be similar with no specialty grains that add unfermentables. Additionally, I usually get around 85% when I mash low in my IPAs and APAs with WLP001, and White Labs lists that max attenuation at 80%. As long as your measuring instruments are calibrated and you are sure that you don't have an infection then you shouldn't worry. If you desire less attenuation then make adjustments on subsequent brews. Mash temp, recipe, and fermentation profile all have an effect on attenuation, so you can make quite a few tweaks that can change your attenuation substantially.