WLP001 - WTF ?

[dunleav1]

I've used WLP001 many times in the past - fermented at 67-70 and got attenuation around 75% give or take a bit.
With that being said I've got a really weird batch going right now.

I did a 1L starter of WLP001 (exp date was like Nov. 2009) on a stir plate for 18 hours. I pitched half this starter in a 1.033 Scottish ale with 2 minutes of direct O2.
I fermented at 67 for 9 days. Fermentation looks ok then no activty in airlock at day 9. I took a reading tonight and I'm at 1.016 for a whopping 51% attenuation.
WTF ?

The hydrometer is ok as I had another batch fermented with wlp002 reach 69% attenuation.

I was hoping to wash this wlp001 yeast and pitch for a few more beers, but it looks like I may need another tube.

Any idea what's going on with this batch of wlp001?

[Henning1966]

You only pitched a half liter of the starter? If so you under pitched by 50% less than you needed according to "www.mrmalty.com" from the info you provided.

[dunleav1]

Being on the stir plate for 18 hours I'm thought I would get plenty of growth - basically doubling the vial.
Maybe I didn't get as much growth as I thought I did or I didn't mix the starter well enough before splittling?

I just gave the carboy a good shaking and bumped the temp up to 73 - if I can tweak a few more points I'll settle.

I've never had wlp001 come up short before - weird.

Guess I'll carb it up and drink it.

[Quin]

You are probably only a couple points high. I think Jamil mentions you don't want these lower gravity beers to ferment too far down or the taste watery. His recipe is meant to have a lot of unfermentables.

[dunleav1]

You are probably only a couple points high. I think Jamil mentions you don't want these lower gravity beers to ferment too far down or the taste watery. His recipe is meant to have a lot of unfermentables.

WOW. I just checked the recipe and the FG is a range from 1.009 to 1.013.
I'm at 1.016 - I thought I was way high but I may have under pitched a bit so I might not be as bad as I thought.

Thanks!