White labs fermentation temp

I used pacific ale yeast and California ale yeast from white labs on my last two brews which are currently fermenting. Normally I ferment around 68* but both viles said the optimum temp was 70-75. I just checked the white labs website and it says the pacific ale should work best at 65-70 and the California at 68-73. Why the discrepency? Which is right?

I'm not sure which is right but I'd try to keep fermentation temp at about 65 myself. A couple of degrees one way or the other shouldn't make a big difference, but I like a nice clean flavor profile for my pales and ambers so I like to shoot for the low side of the temp range. I'm pretty sure the California Ale is about the same as US-05 and I've had good results with that down to 62 degrees. I didn't like the flavors I got in the 70+ range.

I emailed white labs. Here is their (very quick) response:

I'm not really sure why they would say two different things. I would
say that the 70-75 temps are a little high for those strains so that's
probably the less accurate of the two. I wouldn't go so far as to say
incorrect, because the yeast will certainly work in that range an be very
happy doing so, but I think the lower temperatures will give you more of the
flavors that are described in the yeast profile.
As a general rule, higher fermentation temperatures will tend to produce
more esters and phenols then lower temps. Pitching rate, proper wort
aeration, yeast nutrients available and water chemistry will come into play
as well. Both of the strains you are using are very hardy and tolerant
strains so will work over a broad range temps and other variables, so those
are fun strains to play around with to see what kinds of flavors you can
produce.

A buddy of mine just used the European Ale Yeast from WL and noticed the same thing (he's the one who pointed me to the website).

Anyway, problem solved: ignore the directions on the label.

the WL site says 68-73 for Cali and 65-68 for Pacific. Odd that the vials would say differently...

my WL vials say to pitch yeast at 70-75 for optimum start of fermentation nothing about keeping it there.......