Ferment temps - facts vs. myths please..

[TheCookieMonster]

Hi!

When a beer doesn't come out great it's always the brewers fault. It is usually blamed on too high of ferment temps. (never, ever the bad yeast or LME of course.. no.. could never be that!).

From what I've been hearing from Jamil, an exhaustive test was done on stick-on thermometers and they found a 0.5 degree difference between what the thermometer was reading on the outside, to the actual temps inside the middle of the wort where consistent to what the sticker showed on the outside.

My Stickers pretty much show room temperatures.. Maybe a bit above in the first day and night.

I believe Jamil recommends fermenting at 64-70. When the beer doesn't come out, the standard line always gets pulled out: "Well you know, the wort is 5-10 degrees above room temp! It's too high!"

So I am supposed to believe that people are fermenting ale's at 55 degrees which is against what the directions on the yeast and best brewers have to say?

Can someone please separate for the me the facts vs. myth on this?

I just want to be able to know the facts on fermentation temps.

 

[remilard]

I'm not sure I understand your question.

Fermentation temperatures are always quoted (by knowledgeable entities, including yeast vendors) as the temperature of the fermenting beer, not ambient.

If you need at ambient temperature of 55 to have a beer temperature of 65 and that is the White Labs recommended temperature then that is what White Labs recommended.

Who are the best brewers such that Jamil Zainescheff doesn't qualify to be among them?

Here is a fact: You will get the best results from directly measuring and controlling the temperature of the fermenting beer and not the ambient temperature.

Here is another fact: An accurate thermometer taped to a carboy with some insulation (bubble wrap) will measure close to the temperature measured via a thermowell.

Here is another fact: nothing is more important to beer quality that fermentation.

I doubt Jamil Z actually said that the stick on strips will be with .5 degrees since they aren't that accurate in the first place and he has always stressed the need to insulate the temp probe if it is on the outside.

 

[SC_Ryan]

Healthy fermentation is about the most important aspect to brewing a good beer. You have to have sanitary conditions as well of course. Pitch rate is just as important as fermentation temperatures. I would guess if you are still having off flavors from a beer that fermented in the proper range for the strain then you need to address pitch rate and sanitation next.

 

[Beerrific]

Here is another fact: An accurate thermometer taped to a carboy with some insulation (bubble wrap) will measure close to the temperature measured via a thermowell.

I doubt Jamil Z actually said that the stick on strips will be with .5 degrees since they aren't that accurate in the first place and he has always stressed the need to insulate the temp probe if it is on the outside.

+1 to this. I have taped a well insulated temperature probe on the outside of a carboy and a thermometer in a water in the chest freezer, and at the peak of fermentation it was 4-5 degrees lower.

People are not fermenting ales at 55 (unless that is called for). They have the chamber at 55. The ale is fermenting at 60 or whatever the temp controller is set at. The temperature of the beer never gets to 55 because as the temperature of the beer starts to come down, the fridge stops running. The temperature of the surroundings is inconsequential.

 

[Yambor44]

For me, I set the temperature controller probe inside in ambient. Then I have a digital thermometer that I sit about 8 inched away from that. Both just hanging about 12' off the bottom of my fermentation deep freezer.

My temp controller is set so that my digital thermo reads 63 on the low end and 67 on the high end before the controller kicks the freezer on bringing it back down to 63 before shutting back off.

When I rack a beer that has been fermenting for 2-3 weeks, I always note the temperature reading (ambient) on the digital thermometer. Usually it will be 64. Then I take a sample of the beer before I rack it to test the gravity and check the actual temp of the wort. At this point, post fermentation, it is usually dead on or within 1 degree of the ambient reading.

 

[BrookdaleBrew]

I can give you an answer based on my personal experience. I ferment in a room with an ambient temp of around 72F. I keep my fermentor in a swamp cooler with ice bottles switched out twice a day. During the most active fermentation, my fermometer reads a steady 68F but once fermentation is done, the fermometer reads a steady 63F. So I do see the 5 degree difference when I brew.

 

[Yooper]

Poor quality ingredients most certainly DO make bad beer. When we talk about fermentation temperatures being crucial, it's understood that quality ingredients and a quality recipe are used.

If you use a poor yeast strain, and old LME, the beer won't be as good as using a quality yeast and fresh extract. But you can take perfect ingredients and make an undrinkable beer, just by high fermentation ingredients.

I know many people say things like, "My beer ferments at 85 degrees, and it's awesome!" "I use cheap LME kits and corn sugar and ferment at 80 degrees, and it's fantastic". But I would answer "How many competitions have you won with it?" or "How many other brewers agree?".

Some of us have "ugly baby" syndrome with our beer. You know the type- thay have the ugliest baby you've ever seen in your life, but they think little Bubbles is the most beautiful baby ever. Same with our beer. We think our beer is the best beer ever, but the truth is that anybody else with good taste thinks it sucks. Fermentation temperature AND poor quality ingredients are to blame, usually. But for people using quality ingredients, fermentation temperature control and pitching the proper amount of yeast in the fermentation are the most importants factor in beer making.

 

[SwampassJ]

Some of us have "ugly baby" syndrome with our beer. You know the type- thay have the ugliest baby you've ever seen in your life, but they think little Bubbles is the most beautiful baby ever.

Anyone who has ever owned a pug can sympathize with this statement.

 

[Yambor44]

....some of us have "ugly baby" syndrome with our beer. You know the type- thay have the ugliest baby you've ever seen in your life, but they think little bubbles is the most beautiful baby ever...

ahhhhhahahahahaha! :d

 

[AnOldUR]

When the beer doesn't come out, the standard line always gets pulled out: "Well you know, the wort is 5-10 degrees above room temp! It's too high!"

So I am supposed to believe that people are fermenting ale's at 55 degrees which is against what the directions on the yeast and best brewers have to say?

Yeah, you should believe it. The probe for the thermometer marked "ambient" is hanging loose in the fridge. The one marked "carboy" is taped to the side of the carboy and insulated from the ambient air.

 

[backsaw13]

From what I've been hearing from Jamil, an exhaustive test was done on stick-on thermometers and they found a 0.5 degree difference between what the thermometer was reading on the outside, to the actual temps inside the middle of the wort where consistent to what the sticker showed on the outside.

from one fermometors makers site (http://tkachenterprises.com/Products.html)

ACCURACY:
People have often inquired about the accuracy of the fermometer and what it is measuring when placed on the outside of the fermenter in contact with ambient air. To answer those questions, I conducted an experiment where I put warm water in a glass carboy and placed the entire setup outside in thirty degree weather and compared the fermometer to internal temperatures measured by an immersion fermometer as they came into equilibrium.
What I learned is that for every ten degree difference in temperature between the atmosphere and the fluid in the fermenter, the temperature was off by approximately one degree as follow.
0-10 degrees difference between ambient and internal temperature ~ 1 degree difference between fermometer and immersion thermometer
10-20 degrees difference between ambient and internal temperature ~ 2 degree difference between fermometer and immersion thermometer
20-30 degrees difference between ambient and internal temperature ~ 3 degree difference between fermometer and immersion thermometer
So in most normal fermentation situations, the fermometer is only off by about 0.0 - 0.5 degrees from the internal fermenting temperature.

so I don't know if all stick on thermometers are equal - but this seems to support what Jamil mentions

 

[mosquitocontrol]

Yeah, you should believe it. The probe for the thermometer marked "ambient" is hanging loose in the fridge. The one marked "carboy" is taped to the side of the carboy and insulated from the ambient air.

I think I'll have to up my fermentation chamber with some thermometers based off what you have. Now I'm curious where my batches are fermenting at. I've just had the ambient set to 60F and hope for the best.

 

[Yambor44]

I need some clarification on this. I know most folks seem to practice this (taping the probe to the side wrapped in insulation). What I do not understand is how this gives you the inside temp of the wort which is inside the plastic or glass fermenter? To me, of course a probe wrapped in a blanket of insulation would read higher in temp then one hanging in the air.

 

[RegionalChaos]

What about when you have multiple beers fermenting? I am planning a ferment chamber that can hold 30 gallons or so of fermenting beer. Say I brew a 10g batch, and let 2 5g carboys ferment for 1 or 2 days, then I brew another 10g batch, and add 2 new 5g carboys in the chamber... where do I stick my temp probe for the controller? What should the ambient temp be at that point? My current plan is to set the ambient at 64 (based on this though maybe I should go lower) and call it good. I figure if I control the ambient temp, then at least I am controlling ferment temps in a repeatable manner, there for consistent brews. How else could you handle multiple brews fermenting?

 

[TheCookieMonster]

from one fermometors makers site (http://tkachenterprises.com/Products.html)



so I don't know if all stick on thermometers are equal - but this seems to support what Jamil mentions

Thanks!

Anyone have any comments on this?

 

[midfielder5]

Yeah, you should believe it. The probe for the thermometer marked "ambient" is hanging loose in the fridge. The one marked "carboy" is taped to the side of the carboy and insulated from the ambient air.

cool pics and a great demonstration of the issue! thanks!

 

[TheCookieMonster]

Yeah, you should believe it. The probe for the thermometer marked "ambient" is hanging loose in the fridge. The one marked "carboy" is taped to the side of the carboy and insulated from the ambient air.

Can you please explain your thumbnail pic and why you have it in a blanket outside of cooling?

After all, we would all *have* to have fridges to ferment properly if the 10 degree spread was true.

I can say factually that my outside reading much of the time reaches ambient most of the time.

The Coopers can kits says to ferment from 19-27 ambient.

Also, any reason why they sell 'heat belts?'...

Just curious.

I just want to know that's all..

 

[Rundownhouse]

For me, I set the temperature controller probe inside in ambient. Then I have a digital thermometer that I sit about 8 inched away from that. Both just hanging about 12' off the bottom of my fermentation deep freezer.

Good God, that's not a freezer, that's a cave!

I need some clarification on this. I know most folks seem to practice this (taping the probe to the side wrapped in insulation). What I do not understand is how this gives you the inside temp of the wort which is inside the plastic or glass fermenter? To me, of course a probe wrapped in a blanket of insulation would read higher in temp then one hanging in the air.

I believe the thinking is that the insulation protects the probe from the ambient temperatures so that it is directly measuring the surface against which its placed. In turn, the thermal mass of the liquid inside the fermenter is large enough that the actual fermenter material will track pretty closely to what's fermenting inside of it. In other words, 5.5g of beer has a large enough thermal mass that its not going to drop four degrees before the fermenter material changes temp at all. Obviously exactly what the material is dictates how quickly it changes in response to the contents, so the glass of a carboy will track more closely to the temperature of the fermenting wort than will plastic, but in both cases its close enough.

 

[RegionalChaos]

temp control involves heating or cooler to reach a certain temp. If ambient temp in your garage is 40 and you want to ferment out there, you can use a heat belt to bring it up.

 

[RegionalChaos]

How do you handle temp control for multiple stages of fermentation in different vessels sharing the same ferment chamber?

 

[Yooper]

Can you please explain your thumbnail pic and why you have it in a blanket outside of cooling?

After all, we would all *have* to have fridges to ferment properly if the 10 degree spread was true.

I can say factually that my outside reading much of the time reaches ambient most of the time.

The Coopers can kits says to ferment from 19-27 ambient.

Also, any reason why they sell 'heat belts?'...

Just curious.

I just want to know that's all..

I'm not sure I understand your questions. I assume the first one (which I don't understand at all) was directed at Anoldur, so I will let him answer. I doubt he's making up or photoshopping the temperature differentials, so I don't know what your point is.

I've fermented over 250 batches, and very few actually read "ambient" temperature during the first 2-5 days. If you're experience is different, then you'll have to keep during what you're doing. What I do works for me, and the majority of other brewers. I don't have a fridge, since I live in a cool climate. Either my house, laundry room or basement is at a wonderful fermentation temperature all year round. I can always find a good spot, but others aren't so lucky.

Coopers kits do have a range of temperature that is higher than many other kits. I think it's because their yeast is ok at higher temperatures, according to their website. That said, I've only had one Coopers kit, fermented at 68 degrees, and I would never buy another. It was by far the worst beer I ever tasted, let alone made. Other people are happy with the quality and the ingredients, and love those kits. They are quick and easy, and fermenting "hot" does ensure the yeast will work. Cooler fermentations can be more problematic, although result in better tasting beer.

Those heat belts work great if your basement is in the 50s in the winter! I don't use one- I use an aquarium heater in a water bath to bring my beer up to an optimum fermentation temperature.

Remember, beer will ferment at high temperatures, and yeast love hot temperatures. Just because you can do it, doesn't mean it's optimum.

Also, keep in mind that proper pitching amounts are just as important as temperature. If someone underpitches their yeast, and ferments it at optimum temperatures, there still could be some flavor issues. It's not as simple as saying, "ferment all ales at 64 degrees". There are different yeast strains that call for different temperatures, different OG worts call for different amounts of yeast, etc.

You can certainly make beer by buying a Cooper's kit and throwing in some dry yeast and let it ferment at room temperature. You can make excellent craft beer (some as good or better than commercial beers) by purchasing excellent ingredients, pitching the proper amount of yeast, fermentation temperature control, proper sanitation, etc.

I often use the Spaghetti Analogy. You can buy a can of Hunt's Tomato Sauce, and have spaghetti. Or you can buy fresh tomatoes, and make spaghetti. Not the same, but both spaghetti. You can do the same with beer. You can open a canned kit, and make beer. Or you can buy grain, hops, and follow yeast pitching guidelines and temperature. They won't be the same, but they are both beer. It's in the eye of the brewer which they prefer to do.

 

[TheCookieMonster]

temp control involves heating or cooler to reach a certain temp. If ambient temp in your garage is 40 and you want to ferment out there, you can use a heat belt to bring it up.

Oh I see. So everyone buying heat belts are keeping their beers in cold garages?

Why is it on his thumbnail pic that he's indoors and has the carboy wrapped in a blanket?

Actually, why is the wrapping such a common practice to keep it warm? It's in so many pics.

Now I'm reading about fridges and ambient temps at 55?

There's a huge gap in what people seem to be doing and what is being recommended in this thread. I'm just trying to get to the bottom of this.

 

[ChshreCat]

Why is it on his thumbnail pic that he's indoors and has the carboy wrapped in a blanket?

Actually, why is the wrapping such a common practice to keep it warm? It's in so many pics.

It may not be for warmth. Many folks cover their carboys if they can't be kept in a dark place. Keeps them from being skunked. Light causes a chemical reaction in hops that makes them taste and smell bad. That's why most folks bottle in brown glass.

 

[Yooper]

Oh I see. So everyone buying heat belts are keeping their beers in cold garages?

Why is it on his thumbnail pic that he's indoors and has the carboy wrapped in a blanket?

Actually, why is the wrapping such a common practice to keep it warm? It's in so many pics.

Now I'm reading about fridges and ambient temps at 55?

There's a huge gap in what people seem to be doing and what is being recommended in this thread. I'm just trying to get to the bottom of this.

I can't see a carboy wrapped in a blanket in the picture, but if it's not in the dark, it better be wrapped with a towel or blanket! Light is deadly to beer. It'll skunk- ever have Corona? It's in a clear bottle, and light struck, so it's skunky. You want to always keep your carboys in a dark place, or covered. Some use blankets, some use towels, some use t-shirts, some use boxes, etc.

I don't see a huge gap at all between what's being done and what's recommended. I personally don't know one person who actually owns a heat belt. Maybe it'd be useful for fermenting in cool basements, or for making a saison or a Belgian that needs its temperature ramped up, I guess.

Right now, my laundry room is 57 degrees. My cream ale (using S04 yeast) is at 63 degrees. That's perfect for me. When the fermentation slows down, I may move the fermenter someplace warmer to finish up. I don't think that's way out of the accepted brewing practice.

 

[TheCookieMonster]

I doubt he's making up or photoshopping the temperature differentials, so I don't know what your point is.

Would you say his temp differential is normal? That's huge. 10 degree. In that case, why are people buying heat belts and that very same person who posted those pics putting a jacket around his fermenter in indoor temps?

I'm sure he didn't measure those readings after boil. I'm sure he's trying to help get across a point there is a huge difference in temps (although I've never seen one and have never seen anyone stickies read 10 degrees higher).

Makes me wonder why he'd put a jacket around his fermenter in his thumbnail pic.. that's all.

I've fermented over 250 batches, and very few actually read "ambient" temperature during the first 2-5 days.

Oh really? Can you please tell me the temps that you usually get? After all, you have 250 batches under your belt so should know right away. Myself.. I'm just a newb and trying to find out answers.

I don't have a fridge, since I live in a cool climate. Either my house, laundry room or basement is at a wonderful fermentation temperature all year round. I can always find a good spot, but others aren't so lucky.

Any living indoor temp for humans would be too high for fermentation if that picture was correct showing that the ambient temp needed to be in the 55 range. Are you getting this in your house?

That said, I've only had one Coopers kit, fermented at 68 degrees, and I would never buy another. It was by far the worst beer I ever tasted, let alone made.

Oh... I see.. so maybe.. just maybe.. it CAN be the kit and not the ferment temps.. hmmm..that would mean that possibly it's not the brewers fault, it's the garbage LME and not the brewer? After all, you've done 250 batches and have done the same ferment temp for the Coopers and turned out ****ty beer.. the real question is, was it because of ferment temps or lets be honest - an overall ****ty, questionable product.

Other people are happy with the quality and the ingredients, and love those kits.

I like the ugly baby theory.

 

[Duffer]

I read not long ago an interview with a local who had won one of those big contests where some mircobrewery makes your beer if you win (how's that for vague! Shows my weakness for names and details) Been brewing for years and years. Did the schooling to get that certificate. Best ingredients. Always upgrading equipment and processes.

When asked, "What one thing took your homebrewing to that next, premier level?" His response was, "fermentation temperature control."

Most of us aspire one day to get there. As of yet, I don't even know what my ferment temp is! Pantry temp is 68-ish. That's about all I know. Until I have a method of controlling it, I guess I don't wanna know!

...... some day soon tho.....

Also implied but not stated: Fermentation creates heat. Different amounts of heat for different yeasties, for different recipes, for different pitch rates, different oxygenation levels, etc.

 

[ChshreCat]

Your stick on thermometer may also be off. They may be fairly accurate in general, but there's always a bad one.

I'd suggest you do an experiment on your own. Next time you brew, use a probe thermometer to check the temp of the wort in your fermenter once a day, and compare that to the ambient temp using a thermometer sitting next to your fermenter. I bet you'll see differences. Wider differences during the height of fermentation and then it'll get closer and closer as the ferment winds down.

 

[Yooper]

Would you say his temp differential is normal? That's huge. 10 degree. In that case, why are people buying heat belts and that very same person who posted those pics putting a jacket around his fermenter in indoor temps?

I'm sure he didn't measure those readings after boil. I'm sure he's trying to help get across a point there is a huge difference in temps (although I've never seen one and have never seen anyone stickies read 10 degrees higher).

Makes me wonder why he'd put a jacket around his fermenter in his thumbnail pic.. that's all.




Oh really? Can you please tell me the temps that you usually get? After all, you have 250 batches under your belt so should know right away. Myself.. I'm just a newb and trying to find out answers.



Any living indoor temp for humans would be too high for fermentation if that picture was correct showing that the ambient temp needed to be in the 55 range. Are you getting this in your house?



Oh... I see.. so maybe.. just maybe.. it CAN be the kit and not the ferment temps.. hmmm..that would mean that possibly it's not the brewers fault, it's the garbage LME and not the brewer? After all, you've done 250 batches and have done the same ferment temp for the Coopers and turned out ****ty beer.. the real question is, was it because of ferment temps or lets be honest - an overall ****ty, questionable product.



I like the ugly baby theory.

Your post is sarcastic and I've already answered the questions. No one said that ambient temperature needed to be at ambient 55 at all times. I said my laundry room is currently 57, while my fermenting beer is 63. It can certainly be a very good beer even 7 degrees warmer. I like to ferment cooler, though. In my experience, unless I'm hoping for specific yeast esters from higher temperatures, I go to the bottom range of the optimum recommendations by the yeast manufacturer.

In my very first post in your thread, I mentioned that the number 1 cause of bad batches was poor ingredients. Bad batches with good ingredients is usually underpitching and/or lack of fermentation control. I doubt that anybody would disagree with me.

Remilard is an authority (and you ignored his post), Beeriffic is very experienced, and I'm personally had some of AnOldUR's wonderful beers. I've made a few batches myself. Midfielder and ChsreCat have won awards with their beers. If you're truly trying to learn, you'd actually read the answers instead of trying to sound "smart".

I'm done here. Happy brewing!

 

[carnevoodoo]

Would you say his temp differential is normal? That's huge. 10 degree. In that case, why are people buying heat belts and that very same person who posted those pics putting a jacket around his fermenter in indoor temps?

I'm sure he didn't measure those readings after boil. I'm sure he's trying to help get across a point there is a huge difference in temps (although I've never seen one and have never seen anyone stickies read 10 degrees higher).

Makes me wonder why he'd put a jacket around his fermenter in his thumbnail pic.. that's all.

Oh really? Can you please tell me the temps that you usually get? After all, you have 250 batches under your belt so should know right away. Myself.. I'm just a newb and trying to find out answers.

Any living indoor temp for humans would be too high for fermentation if that picture was correct showing that the ambient temp needed to be in the 55 range. Are you getting this in your house?

Oh... I see.. so maybe.. just maybe.. it CAN be the kit and not the ferment temps.. hmmm..that would mean that possibly it's not the brewers fault, it's the garbage LME and not the brewer? After all, you've done 250 batches and have done the same ferment temp for the Coopers and turned out ****ty beer.. the real question is, was it because of ferment temps or lets be honest - an overall ****ty, questionable product.

A 10 degree differential is absolutely something that can happen. If you're fermenting a big beer or using a super active yeast, you're going to have swings like that if you don't keep them under control. Belgian strains are notorious for this, and I've even seen safale-05 take off like a rocket. If not controlled, this will **** up your beer. The temp. fluctuation, the temp. getting too high, and not pitching enough yeast will all have adverse effects on your beer.

I would NEVER let my beer ferment at ambient temperatures, and if I have beer that is outside of my fermentation chamber, it is wrapped in a blanket to minimize light exposure. That's just common sense.

And sure, Coopers kits are probably just going to produce average at best quality beer. It seems you have done little reading into the facts and the science behind yeast reproduction, ester production, and the overall effects of temperatures in brewing. I'm sure someone could turn out a drinkable beer from one of those kits, but I've never tried because I find them questionable. HOWEVER, if you're totally disregarding the need for controlling temperatures, you're more at fault than a kit ever will be.

As for the question posed by someone about multiple fermenters in the same chamber... what I typically do is control the most heat sensitive beer, or target the one with the highest gravity. I have a Wee Heavy at 1.104 and a batch of IPA at 1.072 and I have everything set at 67 degrees. The Wee Heavy had a crazy intense fermentation, but stayed at the temps I wanted. The IPA was slower and fermented at about 64 degrees because it was generating less heat. The freezer was just keeping it cooler. You really just have to watch it and make the best decision for all the beer you have fermenting at the time.

 

[midfielder5]

in the winter, Yes my house can get to 56 degrees overnight... maybe that is the secret

People are trying to help, but Yoop had it right.
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