Author Topic: High Fermentation Temp Question  (Read 3015 times)

Offline raddly

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High Fermentation Temp Question
« on: January 31, 2012, 03:02:56 PM »
A buddy of mine just brewed his second batch--a Two-Hearted clone from Northern Brewer.  In order to avoid light, he placed his carboy box over the fermentor during primary.  Ambient temperature was kept at 67 degrees.  The fermometer showed readings as high as 77 degrees.  This was verified with a second fermometer.  Given, fermentation is an exothermic reaction, but any ideas on why the temp spiked that much?  Was it due to the box used as a cover?

I didn't really have an answer, and told him that it likely wouldn't be a problem.  With that said, he's concerned about fusel alcohol flavors.

Thoughts?

As a corollary, when a recipe lists a target temperature for fermentation, does it refer to ambient room temperature or the fermentation reaction temperature? 

Thanks,
Radd

 

Offline anje

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Re: High Fermentation Temp Question
« Reply #1 on: January 31, 2012, 03:11:11 PM »
Fermentation definitely warms things up, and I wouldn't be surprised if the box provided additional insulation. Putting the fermenter in a dark room (basement, closet, unneeded bathroom) would be preferable.

What I've done to help keep the fermentation temperatures down is to put my fermenter (a 6.5 gallon plastic bucket) in a rubbermaid bin, then filled the bin with cool water to a bit lower than the level of the beer. That lowers the temperature in the fermenter to a couple degrees below room temperature simply due to evaporation. In the summer, I may throw frozen water bottles into the water bath to keep the temperature below 70F, but for now I'm able to keep my fermenter at about 65F in a 68F apartment.
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Offline repo

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Re: High Fermentation Temp Question
« Reply #2 on: January 31, 2012, 03:20:11 PM »
10 degrees is not out of the ordinary. The primary phase will heat up. I doubt the box did more than a degree or two at most. I don't know what yeast was used but I wouldn't worry about it. It's probably fine.

You want to keep the beer in the recommended temperature range for the yeast at least thru primary fermentation (3-5 days on average), temp control here is very important for best results. That said I'm sure his beer will be fine.

Offline tschmidlin

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Re: High Fermentation Temp Question
« Reply #3 on: January 31, 2012, 04:03:46 PM »
I think the box probably played a large role in getting it that warm.  Fusels are a concern, but it might be ok depending on the fermentation timeline, meaning did it get that hot slowly or was the bulk of the fermentation that warm?

Fermentation temp refers to the liquid, not ambient.  The beer is generally 2-6 degrees warmer in my experience, although others report larger increases.
Tom Schmidlin

Offline majorvices

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Re: High Fermentation Temp Question
« Reply #4 on: January 31, 2012, 04:25:38 PM »
That's not too unusual. especially if he pitched warm. say your friend pitched at 74 and fermentation started quickly, that may cause more yeast activity and more exothermic activity. It's best to pitch no warmer than 68 and preferably several degrees below your intended fermentation temp. Regardless, 67-68 degree ambient is simply too warm environment for fermenting most ales. High 50s, low 60s would be ideal. A wet towel with a fan blowing on it may keep the temp down low enough at your recorded ambient temps. Or immerse the fermenter in a container half filled withy water and cycle out frozen water bottles.
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Offline repo

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Re: High Fermentation Temp Question
« Reply #5 on: January 31, 2012, 05:33:11 PM »
I think the box probably played a large role in getting it that warm.  Fusels are a concern, but it might be ok depending on the fermentation timeline, meaning did it get that hot slowly or was the bulk of the fermentation that warm?

Fermentation temp refers to the liquid, not ambient.  The beer is generally 2-6 degrees warmer in my experience, although others report larger increases.

Again I don't have the yeast or ale type info, but if wlp-001 with recommended temp of 70-75  for fermentation was used. Tom you believe that going 2 degrees above that would be cause for concern?

Online dmtaylor

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Re: High Fermentation Temp Question
« Reply #6 on: January 31, 2012, 05:59:20 PM »
I would indeed worry about fusels if fermenting as high as 77 F.  I'd shoot for a maximum closer to 70 F.

Yes, it was the cardboard box that held in the heat.  Next time put it in the basement or outdoors or something to keep temperatures in the 60s.

Fermentation temperatures in recipes ideally refer to the actual beer temperature, not the surrounding air.
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Offline bluesman

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Re: High Fermentation Temp Question
« Reply #7 on: January 31, 2012, 07:01:55 PM »
What temp did he pitch the beer? Has he checked the fermometer against a calibrated thermometer?

I would expect about 6 degrees +/-3 depending on the OG, type of yeast, ambient temp and pitching temp.

Using the box created an insulated environment that will enable the beer to stay warmer longer. An ambient temp of 67 is a good temp for most ales.

I recommend pitching a 1.052 ale using wlp001 at 62F then letting the beer warm up on it's own. It should not heat up much if any beyond ambient temp (67F) if one pitches the appropriate quantity of healthy yeast. The other options are a swamp cooler or a fermentation control chamber.
« Last Edit: January 31, 2012, 07:04:11 PM by bluesman »
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Offline majorvices

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Re: High Fermentation Temp Question
« Reply #8 on: January 31, 2012, 07:24:20 PM »

Again I don't have the yeast or ale type info, but if wlp-001 with recommended temp of 70-75  for fermentation was used. Tom you believe that going 2 degrees above that would be cause for concern?

I'm not Tom, but I did sleep in a Holiday Inn last night. Actually, that's a load of crap. i slept at home last night. But I can tell you that fermentation temp, including pitching temp, is extremely important to the final outcome of the beer quality. You want to be sure to pitch enough yeast, at the proper temps, and then maintain those temps. White Labs and Wyeast both have "recommended temp ranges" and personally I would recommend throwing them out the window or going with the very coolest, or a few degrees cooler than they suggest. This is assuming you are pitching enough yeast and aerating.

All that said, I'm not suggesting the beer is ruined. Only that it could possibly be better. I certainly wouldn't worry too much now, nor would I dump it. A little age will help mellow any fusels that may have developed.

I'd be willing to bet you will both be pleasantly surprised at how well it turns out.
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Offline repo

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Re: High Fermentation Temp Question
« Reply #9 on: January 31, 2012, 08:12:49 PM »
   

Again I don't have the yeast or ale type info, but if wlp-001 with recommended temp of 70-75  for fermentation was used. Tom you believe that going 2 degrees above that would be cause for concern?

I'm not Tom, but I did sleep in a Holiday Inn last night. Actually, that's a load of crap. i slept at home last night. But I can tell you that fermentation temp, including pitching temp, is extremely important to the final outcome of the beer quality. You want to be sure to pitch enough yeast, at the proper temps, and then maintain those temps. White Labs and Wyeast both have "recommended temp ranges" and personally I would recommend throwing them out the window or going with the very coolest, or a few degrees cooler than they suggest. This is assuming you are pitching enough yeast and aerating.

All that said, I'm not suggesting the beer is ruined. Only that it could possibly be better. I certainly wouldn't worry too much now, nor would I dump it. A little age will help mellow any fusels that may have developed.

I'd be willing to bet you will both be pleasantly surprised at how well it turns out.
temp control here is very important for best results. That said I'm sure his beer will be fine.
There are a myriad of things to be done to create the best beer possible.  I can't seem to find any text or other prominent document that say s anything but 80 degrees being the threshhold to stay under. As well as ther being a number of other causes of fusel alcohols. Now I know your feelings about the "experts" opinions and while I find your distrust of wyeast and white labs disconcerting at best. Personal experience does hold more clout. I do wonder how such business's can not only be profitable but even remain in business when they are so misinformed about their own products. I guess all those phd's and labratories were just a waste of time and money.  I am always interested in learning more.

Offline majorvices

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Re: High Fermentation Temp Question
« Reply #10 on: January 31, 2012, 08:37:35 PM »
Repo: first off, WY and WL are selling their vials and smack packs of yeast as "pitchable" when, in reality, there are only enough viable cells in those packages to "properly" ferment a 1.040 ale acording to industry standards - and only then when it is extremely fresh. If you need some documentation to back that up here's a great article: http://www.byo.com/component/resource/article/1749-yeast-pitching-rates-advance-homebrewing

Now, obviously WL and WY are very knowledgeable about their product, and one of the reasons they give the recommended temps is because the amount of yeast they sell in their vials/smack packs are so small. They are assuming you are not going to make a starter or pitch multiple vials, so warmer temps will work better in those cases. So I don't think those Phd's are wasted, they are just trying to cover their bases (and sell a product).

Here's an example of what I am saying: WL and WY both say that one vial of lager yeast is enough to ferment a 5 gallon batch. But they have you pitch it at 65-70 degrees and then start fermentation and lower the temp down slowly over a number of days. Anyone who knows anything about traditional lager brewing practices knows this is not a recommended practice. That is so far below the industry standard cell count as to be laughable - but it allows WY and WL to sell a lager yeast to homebrewers who may not have the equipment to chill down to 44 degrees and grow up a large enough pitch of yeast.

In other words, if someone is looking at homebrewing as a novelty, sure! The temps that WL and WY suggest, along with their pitching rates, are going to work best since you most likely won't be controlling fermentation temps and won't be pitching an "appropriate" amount of yeast. If you want to make the best beer possible you must manage fermentation and this includes pitching rates and temp control.

Regarding fusels, my understanding is they are generated at every fermentation and increase due to different factors, warmer fermenation being one of them. In that case, you should have more fusels at 75 than 65. Wether or not you can discern them via flavor threshold may be a different story but I get better head retention from cooler fermentations (head retention being directly affected by fusels) and ester profiles are certainly cleaner under 70-72.

Also, you may note that WY and WL do not follow the same pitching rates for commercial brewers as they do homebrewers. Commercial brewer's pitches are closer to the cell counts shown here: http://www.mrmalty.com/calc/calc.html (though a bit smaller because the sterols in the cell walls are fortified where as after a fermentation those sterols are mostly depleted) and they overnight your yeast pitch in insulated boxes with ice packs and assume you will be using it with the next day or two (or week at the most). They do ship the vials/smack packs intended for homebrewers in insulated, ice pack cooled boxes but the expiration date is months as opposed to days and most likely if that vial or smack pack is over a week or two old it is in need of a starter even for a 1.040 beer. So you could see why they would recommend warmer fermentation temps.

Wow. that was a long post.
« Last Edit: January 31, 2012, 09:02:58 PM by majorvices »
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Offline tschmidlin

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Re: High Fermentation Temp Question
« Reply #11 on: February 01, 2012, 01:20:50 AM »
I think the box probably played a large role in getting it that warm.  Fusels are a concern, but it might be ok depending on the fermentation timeline, meaning did it get that hot slowly or was the bulk of the fermentation that warm?

Fermentation temp refers to the liquid, not ambient.  The beer is generally 2-6 degrees warmer in my experience, although others report larger increases.

Again I don't have the yeast or ale type info, but if wlp-001 with recommended temp of 70-75  for fermentation was used. Tom you believe that going 2 degrees above that would be cause for concern?
In my experience the high end of the temperature ranges they suggest does not make the best beer.  I'm with Keith on this, keep it cooler and you'll be happier with the end product.
Tom Schmidlin

Offline repo

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Re: High Fermentation Temp Question
« Reply #12 on: February 01, 2012, 07:02:48 AM »
Wow thanks for the insight, I had read palmers byo article, jamil and chris's yeast book, gordon strongs book and palmers book. And I still learn all the time. I never recommended fermenting at high temps or said it was a good idea. I don't know where commercial brewing practices came into a thread about a guy making his 2nd batch of beer. I merely say that hitting a temp a few degrees above the "optimum" range is not reason to worry. Should you avoid that?? Absolutely.  He didn't ask that, it seems that is understood hence the reasoning for the first question.He didn't even have a dark place to ferment. And as to wl and wyeast's temps- what do you think a person on their 2nd brew is doing? Pitching a vial or 2 long before considering getting throughly involved in starters, pitching rates, viability etc. And that person needs to follow the manufacturers instructions. You don't teach people to swim by pushing them in the deep end. Thanks for taking the time to educate me though.

Offline tomsawyer

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Re: High Fermentation Temp Question
« Reply #13 on: February 01, 2012, 08:13:08 AM »
I'd also note that optimum ferm temps are somewhat wamer for commercial fermentor setups.  A big part of that is the use of pressurized fermentations and/or increased pressures generated by the large head of these massive vessels.  This also accounts for the more rapid fermentations reported by the commercial outfits.
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Offline majorvices

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Re: High Fermentation Temp Question
« Reply #14 on: February 01, 2012, 03:20:51 PM »
Wow thanks for the insight, I had read palmers byo article, jamil and chris's yeast book, gordon strongs book and palmers book. And I still learn all the time. I never recommended fermenting at high temps or said it was a good idea. I don't know where commercial brewing practices came into a thread about a guy making his 2nd batch of beer. I merely say that hitting a temp a few degrees above the "optimum" range is not reason to worry. Should you avoid that?? Absolutely.  He didn't ask that, it seems that is understood hence the reasoning for the first question.He didn't even have a dark place to ferment. And as to wl and wyeast's temps- what do you think a person on their 2nd brew is doing? Pitching a vial or 2 long before considering getting throughly involved in starters, pitching rates, viability etc. And that person needs to follow the manufacturers instructions. You don't teach people to swim by pushing them in the deep end. Thanks for taking the time to educate me though.

Not sure what you are talking about. If you read my reply to him I specifically said:

Quote
All that said, I'm not suggesting the beer is ruined. Only that it could possibly be better. I certainly wouldn't worry too much now, nor would I dump it. A little age will help mellow any fusels that may have developed.

I'd be willing to bet you will both be pleasantly surprised at how well it turns out.

I honestly can't tell if you are fussing at me for something or thanking me!  :-\ All I was doing was explaining my point of view about why WY and WL suggest the temp ranges they do. And no where in my post did I ever "push anyone in the deep end" or suggest his beer was ruined. I'm simply stating the importance of fermentation temp. And, FWIW, my long winded post was more directed at you than to the OP.  ;)
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