I harvested some yeast from my last batch and I think I over pitched. The fermentation phase was crazy. The carboy what a full 10 degrees higher than the ambient temp if my fermentation box. The krausen is so thick and high, I can't see through it. Fermentation looked finished after three days. sounds good, but after a week nothing has settled out. I'm worried the yeast is over producing alcohol. I was thinking of cooling it down but I need some yeast left for conditioning.
Overpitching wouldnt really change the way fermentation takes place (temp or overattenuation). Did you brew a beer with a high OG? What strain of yeast did you use?
Pitch rate can affect attenuation. But it's marginal...it's not going to turn your beer into a malt liquor. And yes, cooling it down is/would have been a good idea. You don't say what the temps were, but 10F higher than you wanted doesn't sound good.
I live in Florida so I have to use a fermentation box I made. The box ambient temp on brew day and after was about 65. I figured that would bring the fermenter to about 70 during active time, which is a good temp for WL001. When I checked it in the morning the beer was moving more than I've ever seen, and the temp read 74-76 (I'm never really sure what color is the most accurate on those carbor thermometers.
Whenever I used WL001 in the past it always cleared up pretty early. That's why I'm nervous. The average temp if the carboy after ferm slowed down was and is between 64-68.
There is only so much sugar in wort (especially at 1.050 OG) that can be fermented into alcohol. There is a chance that you may go a big beyond your expected FG, like expecting 1.010, and ending at 1.007, but I wouldn't expect it to go much past that. Something like 1.050 doesn't need a huge pitch of yeast - they say (I haven't tried it in ages) that even a single vial or smack-pack can handle that amount without a starter (I starter everything, out of habit at this point.) If you racked the wort onto a full yeast cake, no wonder things went nuts - that is an enormous pitch for that gravity, especially if things went that much warmer than expected.
Sean Terrill did a Zymurgy article on pitch rate a while back. It was the recommended pitch vs under pitching. Under pitched had a longer fermentation time. Over pitching will have a short lag phase. Pitching on a fresh yeast cake also gives you vey viable yeast.
Actually I harvested and washed the yeast first and divided in two. Then two days before brew day I made a 1liter starter.
This sounds pretty normal to me. The yeast you harvested was probably very healthy and active, and it made short work of the 1.050 wort. The ten degrees over ambient is less than ideal, but WLP001 is such a clean yeast, you'll probably be OK, especially since it didn't get to that temp until high krausen. There could be any number of reasons the krausen is still hanging around after a couple of days. As others have said, it's not because it's over fermenting your beer. I think it's almost always a good idea to let the beer sit for at least a week after active fermentation is done, just to let the yeast clean up, so I would just ... do nothing and let the beer clear. If you can drop the temp, that will help, but even if you can't, the yeast should drop out soon.
On the slow flocculation...I have more experience with Wyeast 1056 than with WLP001, but since they are the same strain... I have noticed slow flocculation/persistent krausen more than a few times. The beer was fine though. Sometimes yeast just does what it does. We know basically what to expect much of the time, but yeast biochemistry is very complex.
This isn't the first time you replied to one of my threads. Actually I think you've replied to all of them. I just wanted to say thanks and I appreciate all you suggestions. You seem to really know your stuff.
