At what temperature does fermentation become "dangerous"?

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MrEcted1

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I had a little mishap this morning... I went into the room where I was brewing and the temp was too high (it was off the scale on the side of my carboy, 78 degrees showed up light blue so it was probably around 80 or more) I had to turn the heat down in the house and crack a window open in hopes to bring it back down to 70-75 range.

I am just wondering at what temperature does it become dangerous for unwanted flavors to appear? I noticed a fruity but slightly rotted smell coming out of my air-lock
 
Dangerous, as in, it will kill you?

A temp spike up to 80 is not going to do anything great to your beer: high temps bring out the estery, fruity flavors in an ale, which I wouldn't consider a positive in a nut brown. But it's not going to wreck it. Yeast don't like dramatic temp changes--closets or pantry cupboards can be good environments because they don't get much airflow or sunlight and therefore tend to not fluctuate in temp as much as other parts of the house.

Ideally you'd probably like that brew to be fermenting at more like about 68-72. Keep in mind that during active fermentation, the fermenting wort generates a few degrees of extra heat above the ambient temp.
 
MrEcted1 said:
I had a little mishap this morning... I went into the room where I was brewing and the temp was too high (it was off the scale on the side of my carboy, 78 degrees showed up light blue so it was probably around 80 or more) I had to turn the heat down in the house and crack a window open in hopes to bring it back down to 70-75 range.

I am just wondering at what temperature does it become dangerous for unwanted flavors to appear? I noticed a fruity but slightly rotted smell coming out of my air-lock
Click to expand...

Whow, what temp do you keep your house at?

Above 75F is definetaly to much for a clean fermentation. You should try to keep it below 70F. Look at the temp range recommended for the yeast that you are using.

Kai
 
I have my house at about 72 degrees. I guess that room is generating more heat then the others. I'll move it to a closet
 
MrEcted1 said:
I have my house at about 72 degrees. I guess that room is generating more heat then the others. I'll move it to a closet
Click to expand...

Do you have any closets, where the back of the closet is an outside wall?
I found that these closets stay coldest during the winter. You could regulate the temp by keeping the door open a little.

Kai
 
I do have a closet I can use... not sure if the wifey wants it there or not.

I did move the fermenter and it made no change... I need a closed area because my house is one level and we have cats that would just love to play with the air-lock

Well... guess we'll have fruity nut-brown ale =)
 
You could sit the fermenter in a tub of water, and cool the water with blocks of ice. It's pretty easy to maintain it 10-15 degrees cooler that way. That also has the advantage of isolating the beer from daily temp fluctuations.
 
I was gonna submerge it in water but decided to try something else... I got a bath towel, got it good and wet, then stuck it in the freezer for about 25 mins to make sure it was nice and cold. I wrapped the towel around the carboy and it's been at a consistent 71 degrees for about 6 1/2 hours now (I made sure the towel wasn't directly touching the thermometer sticker thingie so I would have an accurate temperature). Since this seems to last for quite awhile I will have plenty of time to re-wet and keep the towel cold enough.

Not sure if this is a common "trick" for people that have heat problems, but it's working extremely well for me.
 
MrEcted1 said:
I was gonna submerge it in water but decided to try something else... I got a bath towel, got it good and wet, then stuck it in the freezer for about 25 mins to make sure it was nice and cold. I wrapped the towel around the carboy and it's been at a consistent 71 degrees for about 6 1/2 hours now (I made sure the towel wasn't directly touching the thermometer sticker thingie so I would have an accurate temperature). Since this seems to last for quite awhile I will have plenty of time to re-wet and keep the towel cold enough.

Not sure if this is a common "trick" for people that have heat problems, but it's working extremely well for me.
Click to expand...

Great that it works for you.

I'm not sure if putting it in the freezer did the trick for you. It's probaply just the evaporation that is drawing heat out of the carboy. Just make sure the towel stays wet.

Kai
 
King Kai said:
Great that it works for you.

I'm not sure if putting it in the freezer did the trick for you. It's probaply just the evaporation that is drawing heat out of the carboy. Just make sure the towel stays wet.

Kai
Click to expand...

You're probably right. I was just paranoid (as usual) because the temp was climbing so high... I ended up putting it in the freezer to try and get the heat down as quickly as possible. Seems great though, I woke up this morning and after 9 hours I was at 72 degrees (it gained 1 degree over night... BFD =)
 
Keep in mind that the temperature of the room, even near your fermenter, is likely to be 5-10 degrees cooler than the actual temperature inside the fermenter. So, a room at 75 degrees or more is likely to produce significant esters and other funny (but not deadly!) things in your brew.

If you feel like spending a fair amount, there are fermenters with cooling units that can bring the ambient temperature down 50 degrees from room (or garage, or outdoor) temperature. Of course, $1200 to $2500 is a bit of an investment, more than this happy camper can justify. (example: http://www.morebeer.com/browse.html?category_id=2458&keyword=&x=1&y=1). It is fun to dream, though! Perhaps someone who heats his home to 80 degrees can indulge in such extravagance! :fro:
 
Thor said:
Keep in mind that the temperature of the room, even near your fermenter, is likely to be 5-10 degrees cooler than the actual temperature inside the fermenter. So, a room at 75 degrees or more is likely to produce significant esters and other funny (but not deadly!) things in your brew.

If you feel like spending a fair amount, there are fermenters with cooling units that can bring the ambient temperature down 50 degrees from room (or garage, or outdoor) temperature. Of course, $1200 to $2500 is a bit of an investment, more than this happy camper can justify. (example: http://www.morebeer.com/browse.html?category_id=2458&keyword=&x=1&y=1). It is fun to dream, though! Perhaps someone who heats his home to 80 degrees can indulge in such extravagance! :fro:
Click to expand...

Wow! Those are awesome!

Of coarse... I can't afford one... but maybe if I keep saving my pennies! :)
 
I also have problems keeping beer below 70 degrees. I keep it in a tub of cold water, replacing with cold tap water everyday. When I have freezer space, I keep a one gallon jug of water in there, a second in the tub, and switch them out everyday. This gives me the best results with the least amount of effort.
 

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