Does pitching too hot cause sloooow fermentation?

PapaPorkchop · 04-29-2008, 11:22 PM

I recently started my first brew. I accidently pitched the yeast too hot (way too hot I fear.) It was in primary for 2 weeks, and I was only able to witness a little bit of action. Bubbles slowly and seadily come thru the airlock, and some krausering is visible, but my gravity is still reading .0040 which is actually higher than my OG reading (because of the temp, I assume.)

My question is, though I'm sure fermentation is happening, is it taking super long because i damaged the yeast with my hot wort? Is there anything I should do, or just give it time to work itself out?

It's been in primary 2 weeks, secondary for about 4 days. It's cloudy, and i can see tiny bubbles rising in the carboy.

Any advice?

**Yuri_Rage** · 04-29-2008, 11:26 PM

Yes, pitching at greater than about 90 degrees F can cause some yeast damage. At this point, the beer is fermenting, so just let it go. RDWHAHB!

**the_bird** · 04-29-2008, 11:26 PM

How hot is way-too-hot? REALLY way-too-hot will kill off yeast cells and slow things down (off flavors, too), but we're talking a bit north of ~100° before you get a lot of dead yeast.

**Yooper** · 04-29-2008, 11:30 PM

One thing to keep in mind for next time- don't rack into secondary (actually more correctly called the clearing tank) until it's finished. You slowed it down by racking before it was done, too.
Since it's going, I'd just leave it alone for now. It'll finish eventually!

Tankard · 04-30-2008, 12:49 AM

I pitched the yeast too hot on my first batch and it took about 36 hours to start fermenting. My last batch started at around hour 12 when I pitched it at 80 degrees. So, in my experience, it definitely slows down fermentation.

littlehop · 04-30-2008, 01:13 AM

Repitch,it wont hurt to add more yeast.yes you might need to rack again, but at least you increase your chances of getting beer.

Also try and get wort down to the middle of your fermenting temp range before you pitch. lower temps. also mean more oxegen can get dissolved for your yeast to use.

chears

PapaPorkchop · 04-30-2008, 03:11 AM

Thanks for the input, guys. Here's how it happened.

I forgot to put my thermometer strip on the fermenter. I put the cool water in the fermenter. I added the hot wort and waited about half an hour while my yeast was hydrating. Then i went ahead and pitched the yeast when it was ready. When I remembered the thermometer, I slapped it on, and it was still so hot that it took another 45 minutes before I got a reading (the strip only goes up to 80c.) So I have no idea how hot it was. As I say, it does seem to be fermenting, but It is a pretty big beer with alot of malt, and I want to make sure I take full advantage. I tasted a little and it was pretty sweet still.

Is it worth the risk of contaminating the beer to pitch some more yeast, or am I better off letting it ride for an extra couple of weeks and waiting for the bubbles to stop?

PS, I've also heard putting some ice in the fermenter before the hot wort is added can help the cooling process immensely. Is this recommended?

beta pleated sheet · 04-30-2008, 04:12 AM

Quote:

Originally Posted by the_bird

How hot is way-too-hot? REALLY way-too-hot will kill off yeast cells and slow things down (off flavors, too), but we're talking a bit north of ~100° before you get a lot of dead yeast.

Yep. For most critters that live in medium temperatures (including yeast and humans) 107 is about the point where some ezymes start to denature. Meaning, this is when it really gets dangerous.

For future reference, I recommend getting your wort a few degrees below target temp before pitching yeast. Fermentation actually gives off a good bit of heat.