S05 at 20+ celcius?

[Jake]

I've never brewed with it at this warm of a temp. The room temp was held at about 20 degrees, so likely fermenting a bit higher.

I had a blowoff tube set up and after 24 hours it was honestly like somebody was blowing through a straw. It was a constant airflow, literally 20 bubbles or so per second. Got a nice thick layer of krausen on both of my 5 gallon carboys, and then it completely dropped out after about 50 hours. Brewed this on Sunday and there is hardly any blowoff tube activity now (maybe a bubble a minute), indicating that fermentation is either done or almost done. I plan to take a hydrometer reading tonight to see where I'm at.

Typically when I brew with S05 around 17 degrees, its about 2 weeks to get to where I'm at now (usually pretty slow to drop out).

Any predictions on what to expect? I'm used to it being a pretty clean yeast and that's what I'm hoping for, so should I be worried?

[fakr]

that is a fast fermentation for S-05.  I typically set my room temp to 18, and my fermenters are 2 degrees warmer (20C) during fermentation.  When fermentation is done, they drop down to room temp.  this usually takes 5-6 days max to finish up.

I have fermented at 22-23C with S-05 before, and found a slight, very slight apple taste, but not half as bad as S-04.

[Richard]

My guess would be acetaldehyde like fakr suggests, also potentially higher levels of esters (fruity flavours) and fusels (magic marker). If this was a low-gravity brew (1.040 or below) it may have just made fast work of the sugars, given the extra heat.

Regardless you can deal with the acetaldehyde by just leaving it on the cake for a few days; ditto any other off-flavours that you could actually do anything about at this point.

[fakr]

could mash temp play a role in this as well?  higher mash temp, less fermentable sugar, thus less time to ferment out?  

just throwing that out there....

did you take a hydro reading yet Jake?

[Richard]

Yeah could do, although I can't say with certainty as the yeast might take longer to process the more complex sugars from a higher-temp mash.

[Jake]

Mased at about 152. Came out around 1.055. Like it to finish around 1.010 to 1.012

[Richard]

So what's it at right now?