Fermentation Temp Ok?

I was really careful about selecting a good spot for the primary before brew day that was a constant 65-68 degrees. Making a Bavarian Hefewiezen with Wyeast smack pack. Made a 600ml starter two days before with home made stirrer from stuff around the house (cept stir bar itself). What I didnt anticipate was the massive exotherm I am getting. The thermometer (not too accurate I assume) is reading 74 degrees. General consensus be that I need to wrap in wet towels put a fan on it?? Or..will it be fine where it is in the basement with the 6 degree exo going???

Must have posted in the wrong section.

It's not uncommon for the active fermentation to raise the wort temp 5°-7°. Sound like that's what you have going on. Any other beer and I'd be concerned, but considering it's a Hefe, I would just leave it alone.
Bul

You'll just have to wait and see. My first beer was a hef I fermented in my pantry during the winter and it came out great. A couple months later I made another hef and an oatmeal stout both came out cidery tasting. Since I've bought a temp controller and freezer and have had no more cidery beer. If it didn't ferment to hot you'll just get more bannana and clove flavors which some ppl do as personal preference. Or it will come out fine.

Off gas smells like a Monkeys burp. Not that I know what that's smells like.. I went ahead and wrapped it in wet towels and its at 68 now. Still bubbling and belching away...temp change like that have the potential for off flavors?

Weeezle007 said:

Off gas smells like a Monkeys burp. Not that I know what that's smells like.. I went ahead and wrapped it in wet towels and its at 68 now. Still bubbling and belching away...temp change like that have the potential for off flavors?

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Any time i've had temp changes like that, yeast get pissed off and start letting off sulphur compounds. Most of the time these compounds condition out.

I have brewed for about a year in a very stable 65 degree basement. I finally slapped on a thermometer strip that showed a fermentation temp of 75. If anything an underestimate. In retrospect, I can taste esters in many of my lighter brews.

Just recently purchased a cool brew which has done a nice job of keeping my fermentation temp around 63. I just have a batch or Biermunchers cream of 3 crops in it now. It has notably slowed the fermentation. My first time brewing this beer, it was down to final gravity in 3 days. Now it is still above final gravity 8 days into the primary and has a kreusen. Its like a movie in slow motion at a slightly lower temp. I think this is anticipated with a drop in the temperature of 10 degrees but does this seem reasonable? I'm using WLP001 as my yeast so I'm on the low end of the yeasts temp range

When fermenting on the cool side it's even more important to have a healty pitch of active yeast. A starter on liquid yeast will wake up the yeast and get them ready for the job.
I usually ferment on the cool side and most of my fermentations are complete in about 5 days.
Another thing you will need to do with a cooler ferment is to warm up the fermentor towards the end of fermentation for a d rest.
Good luck
Bull

So can the stick on thermometers be trusted or is it just assumed that the temp inside is higher than what it's reading? If so, if I want to ferment at 65F and the thermometer says 65F, so I try to cool it even lower?

Temp control is very important, BUT it is less important with some yeast strains. Hefe strains are one of those that you can really let ride into the higher end of the temp range (mid 70s), which will increase ester production (banana-type flavors) and you'll still get a great beer. So RDWHAH, your beer is going to be fine. You should worry more about temp control with other strains, though, and in that case you should account for an active fermentation being 5-10 degrees warmer than the ambient temp.

is this temp control more important just thru the vigorous fermentation (first 5-7 days). or, is it a must to maintain this constant temp of, lets say 65 deg for the 4 weeks in primary sitting on the trub? sorry to ask but some days i forget to replace the ice in my swamp tub.

grimzella said:

is this temp control more important just thru the vigorous fermentation (first 5-7 days). or, is it a must to maintain this constant temp of, lets say 65 deg for the 4 weeks in primary sitting on the trub? sorry to ask but some days i forget to replace the ice in my swamp tub.

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I routinely let my beers go up to 70-71 after active fermentation slows. For me, that's usually 4-6 days. It seems like the clean-up stage is helped by this warmer stage as my beers come out very clean. Above 71-72 YMMV.

Great information! Thanks for the help. I am not sure it ever got as warm as I might think. Some people describe seeing 3 bubbles per second in the airlock. I have only witnessed it pushing through all the way about once every 3 or 4 seconds at its fastest. And now after 3 days its still only once every 6 or 7 seconds. The wetted towels and ceiling fan have kept it around 65.

I wonder what a slowed down fermentation rate would be? If its popping through the airlock at say once every 10 seconds would that be considered slow enough to take the towels off? Great forums...love it!

EDIT: I need to learn to read.

That said, I have used the warming at the end for styles from pale ale to RIS without any problems.

Its a Bavarian Hefe tho.