Fermentation Temps:Ambient,Outside of fermenter,Inside at high kraeusen

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RCCOLA

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I've seen a lot of posts about ferm. temps as related to ambient temp,and ferm. temps on the outside of the fermenter as opposed to the inside of the fermenter at high kraeusen.Everyone has an opinion but noone posts any facts about it.I have been guilty of posting about temps being this or that as related to outside temp., or the inside of the fermenter being X amt of degrees hotter than the outside w/o any facts to support it.
So,I checked all the temps. of my last fermentation and was suprised by what I found.
I ferment in a wine fridge so it has a small area around the fermenter so this may account for the small difference in ambient to ferm. temps.
Inside chamber:66F.
Outside fermenter high kraeusen:67F
Inside fermenter 2inches into beer at high kraeusen:67.5F-68F
This was all measured w/ a lab.thermo. and a fairly vigorous fermentation on a brown ale w/ S-05 yeast.After about 5 days the o/s of the fermenter had dropped to the same temp as the chamber and the gravity had stabilized.
Anyone else log any of their temps in regard to this?
 
I have not done this, so thank you for posting that data.

I seem to recall Bobby_M posting something a long time ago on this. He pitched a barley wine on a yeast cake and documented and active fermentation temp that was 10F over ambient temp. Of course, pitching a barley wine on a yeast cake is probably the most active ferment a homebrewer is likely to achieve, so his result may be an upperbound.
 
I have a set-up where I can monitor the fermentation temp inside the fermenter using a bimetal thermometer that i calibrate right before I set it.

Most of the time femrentation temps run ~4F (give or take a degree or two) warmer than ambient temps. But everyonce in a while it goes nuts. That's why i watch it closely for the first 24 hours and adjust the ambient temp accordingly. I did an English IPA last Feb. I wanted it to ferment on the upper edge on the yeasts (wlp005) temp range to get good attenuation (005 is highly flocculant). I pitched at 68 that night and in the morning it was 78F in the fermenter! It ended up like a belgian IPA. Lots of esters, phenolics, and even some fusel alcohols. It was vile. it was some crazy s^$*t.

When it is a few degrees higher it is easy to bring the temp down. When it is 10F higher....It's like trying to move my fat ass when I'm drunk.
 
I use a laser for spot checks inside the carboy. I have had temps inside vary from ambient 8 degrees (specifically with belgians using large starters)
 
I have a set-up where I can monitor the fermentation temp inside the fermenter using a bimetal thermometer that i calibrate right before I set it.

Most of the time femrentation temps run ~4F (give or take a degree or two) warmer than ambient temps. But everyonce in a while it goes nuts. That's why i watch it closely for the first 24 hours and adjust the ambient temp accordingly. I did an English IPA last Feb. I wanted it to ferment on the upper edge on the yeasts (wlp005) temp range to get good attenuation (005 is highly flocculant). I pitched at 68 that night and in the morning it was 78F in the fermenter! It ended up like a belgian IPA. Lots of esters, phenolics, and even some fusel alcohols. It was vile. it was some crazy s^$*t.

When it is a few degrees higher it is easy to bring the temp down. When it is 10F higher....It's like trying to move my fat ass when I'm drunk.
This is why I've started pitching around 60F.Think about it-you pitch on the upper end of where you want your fermentation temps to stay and when that yeast goes off,sometimes it's like a runaway train.Pitch lower and the ferm. will start slowly and allow you to reign in the temps.I think a lot of brewing texts have failed noobs by saying to pitch below 76F.IMO, that beer will have fermented too long at too high of a temp. to end up really good.
 
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