WLP 001 Over Attenuation?

[Vintage63]

Hey Everyone,

I was hoping someone could give me some guidance on why WLP 001 seems to be attenuating so high on my last handful of recipes. I have been brewing american pales and IPAs and use BeerSmith everytime. Every beer is finishing well below BeerSmith estimates (1.008) with a measured apparent attenuation of 87%.

I temp control in a chest freezer with the probe attached to the outside of a glass 6 gallon carboy with tape and bubble wrap. I start cooler at 65F for a day or 2 and let it free rise to 68F to finish. I always use Mr. Malty pitching calculator and make appropriate starters several days prior to brew day.

What the heck am I doing wrong? White Labs calls for 73-80% attenuation. Thanks guys.

 

[jddevinn]

Are you sure that your OG reading is correct?

 

[jerbrew]

It could be a combination of things. Inaccurate readings of OG and FG are one of them. Those are also only average attenuations. what temp are you mashing? What's the recipe like? I just did an IPA with wyeast's chico (1056?) and ended up with an 85% apparent attenuation mashing around 148. I don't think there is anything necessarily wrong.

 

[DocScott]

Agreed with jerbrew. Check the calibration of your thermometer, maybe you're mashing lower than you think. Are you using simple sugars that ferment out completely? Are you using a hydrometer or refractometer for gravity readings?

 

[beskone]

If I make a starter on any beer that's < 1.070 WLP001 almost always finished around 1.008 (fermented at 66º)

Next batch I'm mashing higher and fermenting colder ~64º to try and keep it more under control.

 

[Morrey]

I just made a pumpkin ale with wlp001. It started at 1.050 and finished at 1.012. That's pretty much inline with my previous experiences. I used a temp controller at 68F. However I mashed at 154F knowing I wanted the ale to finish with a hint of sweetness and a bit more body for my tastes. It dropped right in as planned.

Are you mashing around 148F and creating lots of short chain sugars that are highly fermentable?

My rule of thumb is for a beer to finish drier and thinner, mash around 148F. For a beer to finish a bit less dry and fuller body, try 154F. Just my .02.