How important is temperature to fermentation? And do lower temps slow the process?

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snarf7

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I put mine in the basement because it's dark and a consistent cool temp (summer it might get up to 65, right now it's about 60-61 F). But I've also read that the fermentation process itself is exothermic so the carboy is going to be warmer than the air around it, so cooler might be better no?

Obviously lagering is a different deal, but for ales and wheat beers is it fairly forgiving? I've just started brewing this year and they seem to be turning out really well (when I don't **** something critical up that is...for example, doubling the amount of fermentables because I was mixing and matching metric and imperial :D) Are there certain styles (outside of lagers that I mentioned) that are more finicky with temp?

If it's more important to maintain a constant temp rather than hit a perfect number then I'm probably in good shape, I was just curious if lower temps slow down the fermentation process so it might take a little longer in the winter than in the summer?
 

gunhaus

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I think temp control along with sanitation are the most important factors in brewing - Just me, but i bet there are others with similar thoughts.

Lower temps affecting ferm rate are very dependent on the yeast in question, and will vary wildly across the spectrum/
 

Qhrumphf

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It's gonna depend on a lot of factors, but yeast strain is a big one. Some strains are far more picky than others.

The problem you can run into controlling by air indirectly (as opposed to controlling directly by the beer) is that as fermentation slows, the temp may start to drop, especially in smaller volumes (larger volumes the thermal mass helps to hold it longer).

Some strains can handle this without issue. Some strains (many English and a few Belgian strains) may start floccing prematurely, and underattenuate or stall. Especially with English strains this can leave some significant diacetyl.

What you can do is surround your fermenter with water (put it in a plastic tote bin and fill with water to the level of the beer). Water insulates far better than air, and increases the thermal mass, keeping your fermentation temp more stable and essentially pinning it to the ambient temp. If you wanna get fancy, an aquarium heater or more frequently soda bottles or milk jugs of ice can adjust the water temp, and accordingly your fermentation temp. It's VERY difficult to keep stable lager temps stable this way, but I've done it before. If you want lagers a fridge is your best bet.
 

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There are many yeasts and each has it's preferred range. That being said, they are pretty forgiving. Some of us build fermentation chambers with temp probes and try to keep the INITIAL TEMPS to a certain point in order to repeatably make the same recipe, the, um, same. Many many MANY others do fine setting the fermenter in an old shoe closet and letting it go. Or shirts. Beer doesn't care. But yeasts that have a range, like S05, will for some, put off peach esters when on the cooler part of the range like low 60's Farenheit. Some yeasts will go apopletctically nasty when fermented warm. The main thing I try to do is to keep the yeast within a degree of the middle of the range when I first use it, for the PRIMARY FERMENTATION -- that is the first few days. After I see that the exotherm has happened, it really doesn't matter too much what you do to it. Then if I try someone's recipe and it calls for a certain temp with a certain yeast, that is what I'll do. There's a lot of variables out there and getting them all under control is like herding cats. Or two year olds.

{EDIT: annnnd @Qhrumphf beats me to it}
 

gunhaus

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There are many yeasts and each has it's preferred range. That being said, they are pretty forgiving. Some of us build fermentation chambers with temp probes and try to keep the INITIAL TEMPS to a certain point in order to repeatably make the same recipe, the, um, same. Many many MANY others do fine setting the fermenter in an old shoe closet and letting it go. Or shirts. Beer doesn't care. But yeasts that have a range, like S05, will for some, put off peach esters when on the cooler part of the range like low 60's Farenheit. Some yeasts will go apopletctically nasty when fermented warm. The main thing I try to do is to keep the yeast within a degree of the middle of the range when I first use it, for the PRIMARY FERMENTATION -- that is the first few days. After I see that the exotherm has happened, it really doesn't matter too much what you do to it. Then if I try someone's recipe and it calls for a certain temp with a certain yeast, that is what I'll do. There's a lot of variables out there and getting them all under control is like herding cats. Or two year olds.

{EDIT: annnnd @Qhrumphf beats me to it}
While I am willing to believe that it would be possible under absolutely correct conditions to herd cats - i will NEVER subscribe to the possibility of herding 2 year olds . . . . . As for the beer stuff: Good info.
 

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Once you brew certain styles with various yeasts you'll find quirks at certain temperatures. Not all yeasts will act alike. One of the first liquid yeasts I used was WLP300, and one of my favorites is WLP029. Both are ale yeasts but react differently under similar conditions. I learned real fast German hefe yeasts can be pretty vigorous fermenters!
First off, ALL my ales and lagers are brewed in primary at ambient temps between 58F-62F for two to three weeks, then bottle carbed another three weeks at the same temps before drinking. When they're ready, the bottles go into cold storage just above freezing. My preference leans toward Continental styled, lager-like ales so that's how my method works for the most part.

The two easiest things to control, in my opinion, is your sanitation and fermentation temperatures. The yeast ... well, they do they will, but it's a good idea to know your yeast traits to get the best character from it you can.
 
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kh54s10

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Fermentation temperature control is one of the best places to look in making your beers better.

You are lucky that your basement temperatures are fairly steady and in a decent range for ales.

I have always wondered about peoples basement temperatures. In the summer my basement always got into the low 80s and in the winter with the furnace down there it was rarely in the mid sixties - upper 60s was normal. So I needed to cool year round.
 
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snarf7

snarf7

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Lower temps affecting ferm rate are very dependent on the yeast in question, and will vary wildly across the spectrum/

I think you misunderstood my question...i'm not trying to equate all yeasts as equal and ascribe a single temperature range to them or anything like that. I recognize that they have different ranges. What I was wondering is 'within the range for a given yeast (lets say it's 55-75F for kicks), does fermentation slow down as you lower temperature?' In other words, does the same yeast ferment much slower at 55 than it does at 65 or 70 etc?
 

Qhrumphf

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"In general", with heavy caveats, yes, lower temp means slower ferment.

Some yeasts handle it better than others though, so ultimately it's still strain dependent. Some strains will perform well below or above their stated ranges IF manipulated properly. Just have to know your yeast.
 
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snarf7

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"In general", with heavy caveats, yes, lower temp means slower ferment.

Some yeasts handle it better than others though, so ultimately it's still strain dependent. Some strains will perform well below or above their stated ranges IF manipulated properly. Just have to know your yeast.

Yeah again, I'm not comparing yeast strains with this question, I'm not sure how to make it clearer.

Lets see...1)I'm not asking if US-05 will perform better at low temp than Wyeast 1028 (or any other strain you can think of)...and I'm not asking if 2)US-05 will be more adaptable at low temp than 1028 (or any other option). What I'm asking is if the drop in temp universally slows them all down (not by the same amount, mind you, see #1 and #2 above)...what I'm trying to establish is if lowered temperature always slows the fermentation process? Basically, is there a yeast that ferments better at a lower temp than a higher temp (WITHIN ITS OWN PRESCRIBED RANGE)? If there is not then I have my answer, if so, please explain
 
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snarf7

snarf7

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I have always wondered about peoples basement temperatures. In the summer my basement always got into the low 80s and in the winter with the furnace down there it was rarely in the mid sixties - upper 60s was normal. So I needed to cool year round.

really old farmhouse dude...the entire basement is below grade and the walls are fieldstone and mortar and 3 ft thick :D Nearly constant temp and humidity, I understand now why natural wine cellars were such a big deal back in the day. Also just the idea of having a root cellar for storing vegetables and preserves through the winter. As it turns out it's a really good spot for beer too.
 

Qhrumphf

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Yeah again, I'm not comparing yeast strains with this question, I'm not sure how to make it clearer.

Lets see...1)I'm not asking if US-05 will perform better at low temp than Wyeast 1028 (or any other strain you can think of)...and I'm not asking if 2)US-05 will be more adaptable at low temp than 1028 (or any other option). What I'm asking is if the drop in temp universally slows them all down (not by the same amount, mind you, see #1 and #2 above)...what I'm trying to establish is if lowered temperature always slows the fermentation process? Basically, is there a yeast that ferments better at a lower temp than a higher temp (WITHIN ITS OWN PRESCRIBED RANGE)? If there is not then I have my answer, if so, please explain
We've answered your question multiple times.

Then answer is "usually" but not "always". It's strain dependent.

One strain may ferment like a rocket until you push it low enough it doesn't ferment at all.

Another may ferment slowly no matter what unless you kick it high enough to throw off flavors.

*most* strains will slow with colder fermentation until they get too cold and either throw off notes or stall entirely.

And even then it's still dependent on your process and equipment.

You're not gonna get an absolute answer.
 
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snarf7

snarf7

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We've answered your question multiple times.

Then answer is "usually" but not "always". It's strain dependent.

One strain may ferment like a rocket until you push it low enough it doesn't ferment at all.

Another may ferment slowly no matter what unless you kick it high enough to throw off flavors.

*most* strains will slow with colder fermentation until they get too cold and either throw off notes or stall entirely.

And even then it's still dependent on your process and equipment.

You're not gonna get an absolute answer.

No you haven't. You insist on answering your own question instead of the question I actually posed. Typical internet forum behavior, it's much more fun to tell the person their question is stupid (in a beginner's forum nonetheless!) than actually answer the question right?

If you can't answer the question that's fine, please step aside and allow someone more versed on the topic to respond, But continuing to ignore what I've taken great pains to spell out and answering questions I never asked is not serving anyone except your own ego.

It's really dead simple. "IS THERE A YEAST THAT FERMENTS FASTER AT LOWER TEMP THAN HIGHER WITHIN ITS PRESCRIBED RANGE"? Yes or No. Simple question. And if your answer at this point is still 'it depends' and you still can't explain which yeast that is and why it behaves that way then don't even bother, because you clearly don't 'get it'
 

Qhrumphf

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No you haven't. You insist on answering your own question instead of the question I actually posed. Typical internet forum behavior, it's much more fun to tell the person their question is stupid (in a beginner's forum nonetheless!) than actually answer the question right?

If you can't answer the question that's fine, please step aside and allow someone more versed on the topic to respond, But continuing to ignore what I've taken great pains to spell out and answering questions I never asked is not serving anyone except your own ego.

It's really dead simple. "IS THERE A YEAST THAT FERMENTS FASTER AT LOWER TEMP THAN HIGHER WITHIN ITS PRESCRIBED RANGE"? Yes or No. Simple question. And if your answer at this point is still 'it depends' and you still can't explain which yeast that is and why it behaves that way then don't even bother, because you clearly don't 'get it'
Drop the attitude mate. We've answered your questions as you've asked them. That's not the question you asked.

You asked if fermentation slowed with lower temp. The answer is usually, but different strains react to temp differently.

Then you asked if fermentation ALWAYS slows. The answer is no- some strains will ferment quickly throughout their entire range or even a bit below it, with no appreciable speed difference.

I am not aware of a strain that will ferment slower at warmer temps than it will at colder temps. That doesn't mean that one doesn't exist, but it'd be highly unusual (but once you start dealing with out there yeasts like some of the wild yeasts out there now, who knows). In my experience speed of fermentation directly correlates with temp, but can vary between not a noticeable difference at all to a significant difference (days vs weeks of ferment time), with or without flavor differences.
 
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