WLP 051 Fast Krausen dissipation and sulfuric odor

I recently(today is sat, brewed on thurs) did a 10 gallon batch of 1.062 pale ale, with which I used 2 purepitches of White Labs Cali V to make a 1300mL Starter. Just now while cleaning aaround the house I noticed the sulfur smell and went to check on the carboys. The one I noticed had a significant reduction in krausen since I last checked on it, which was last night around 11pm. Now I have used this yeast before particularly in my last batch which i brewed roughly 3 weeks ago but that was the standard vile from WLP and did notice the sulfur smell durring fermentation however not as potently and that batch was a much smaller beer having an OG of 1.036. Could the yeast really have fermented out that quick to where the krausen is falling? or is this a slightly atypical thing for the strain to do? it just seems awfully fast the ambient temp in my house is 64. I dont know how it could have gotten infected as i clean and sanitize everything with 5 star products. has anyone experienced this before?

Ambient temp doesn’t matter…beer temp does.  What’s the temp of the beer?

thermometer on the carboy reads 70. So I’m right at the top of the range but would think it would be okay, correct?

I have a similar question. I did a starter on some yeast I harvested 2 months ago from an APA made with a culture made from a bottle of Mirror Pond. That original batch came out great; fermented out in less than 2 days. I saved a vial of cake. it has a sort of acrid smell, i cant describe, just not the usual smell i have come to expect. I pitched it last night and now the room where the carboy is has the same smell. Wife says sour, like sour milk. Could the yeast be bad? First batch didnt smell like this.

Not necessarily, but maybe.  I find the temp ranges listed to be higher than I think makes the best beer.  At the very least, using a temp that high will accelerate fermentation.

i will throw out there based upon my experience and pure pitch, using two packs and a starter was way over pitching. that coupled with warm temps and you probably fermented at a very accelerated pace.

edit: realized 10 gal not 5. i still only use 1 pack pure pitch less than 1 month old for 5 gals…no starter.

Yea I will say the pure pitch I had was unlike any vile I’ve used from white labs. It was essentially a solid mass of yeast cake. Very intense. It’s just weird that they are fermenting with little to no Krausen.

More important is how it tastes. Smells during fermentation aren’t very indicative of a final product usually.

Possible it started quickly and finished just as quickly. Healthy, large qty and higher temps could produce a fast and furious fermentation that burns out and starts winding down quickly.  Taste will confirm, so wait until then and see.