# Warmer constant temps vs fluctuating cooler temps for fermenting?

**URL:** <https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254>\
**Category:** Ingredients\
**Created:** [July 27, 2014, 12:10pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254 "2014-07-27T12:10:04Z")\
**Posts on this page:** 20\
**Page:** 1

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**Author:** ![Lazy\_Ant\_Brewing](https://avatars.discourse-cdn.com/v4/letter/l/b9bd4f/32.png) [@Lazy\_Ant\_Brewing](https://forum.homebrewersassociation.org/u/Lazy_Ant_Brewing)\
**Post date:** [July 27, 2014, 12:10pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/1 "2014-07-27T12:10:04Z")

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I’m getting ready to brew again and I’m wondering about trying to use a swamp cooler to obtain a cooler fermentation temp, but since I’m away from the house up to 16 hours some days I’m not sure I can change the ice often enough to maintain a stable temp.

First some background.&nbsp; I live in a ranch style house (no basement or cellar) in the Ohio River Valley where August temperatures outside are usually 93 F plus ( above 100 F also happens sometimes) with very high humidity.&nbsp; Since I spend some time outside tending a vegetable garden, I like to keep the thermostat set at 73 F inside the house just to moderate the"themal shock" you can get when you step outside.

I’ve brewed several&nbsp; different ales in a spectrum from amber to stout using safale US-05 dry yeast and fermenting at 73F in the warmer months of the year.&nbsp; To my taste, they turn out to be quite drinkable.

Questions:

First, how important is it to maintain a stable temperature to keep “happy” yeast when you are fermenting?

How hard his it to maintain a stable temp with a swamp cooler?&nbsp; How often do you need to change the ice etc.? I live by myself and I am away from the house for 8-10 hours most days and sometimes more.

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**Author:** ![BrewBama](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/brewbama/32/21184_2.png) [@BrewBama](https://forum.homebrewersassociation.org/u/BrewBama)\
**Post date:** [July 27, 2014, 12:16pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/2 "2014-07-27T12:16:48Z")

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I do not have experience with the swamp cooler method. However, I understand it works quite well. I’ve read that ice is added twice daily. I take that to mean once before work and once before bed.

Like you I don’t have lagering capability so I brew what the season’s ambient temp gives me in my basement.

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**Author:** ![ynotbrusum](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/ynotbrusum/32/10316_2.png) [@ynotbrusum](https://forum.homebrewersassociation.org/u/ynotbrusum)\
**Post date:** [July 27, 2014, 12:47pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/3 "2014-07-27T12:47:01Z")

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Use one pint frozen water bottles.&nbsp; You can put more of them in the water for the longer period and fewer in for the overnight. It’s not a perfect science, but the yeast will still appreciate the cooler temps.&nbsp; Or explore the wonderful world of Saisons at those temps - you may need a brew belt for nights, but the daytime temps will work great with Saison yeast.

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**Author:** ![Lazy\_Ant\_Brewing](https://avatars.discourse-cdn.com/v4/letter/l/b9bd4f/32.png) [@Lazy\_Ant\_Brewing](https://forum.homebrewersassociation.org/u/Lazy_Ant_Brewing)\
**Post date:** [July 27, 2014, 1:04pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/4 "2014-07-27T13:04:33Z")

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Thanks guys for the advice!

Now that I think about it, if I bought a child’s plastic swimming pool, I could probably switch out gallon milk jugs filled with ice.

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**Author:** ![cempt1](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/cempt1/32/9922_2.png) [@cempt1](https://forum.homebrewersassociation.org/u/cempt1)\
**Post date:** [July 27, 2014, 1:05pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/5 "2014-07-27T13:05:06Z")

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> [@ynotbrusum](#):
>
> Use one pint frozen water bottles.&nbsp; You can put more of them in the water for the longer period and fewer in for the overnight. It’s not a perfect science, but the yeast will still appreciate the cooler temps.&nbsp; Or explore the wonderful world of Saisons at those temps - you may need a brew belt for nights, but the daytime temps will work great with Saison yeast.

+1 to the saison idea.&nbsp; I live in south east Alabama.&nbsp; I have a beer with the saison yeast going in the garage right now. There is a good thread on this yeast in the yeast section. I did the reverse of the swamp cooler and put a 17 dollar aquarium heater in it to hold it steady.

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**Author:** ![duboman](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/duboman/32/5890_2.png) [@duboman](https://forum.homebrewersassociation.org/u/duboman)\
**Post date:** [July 27, 2014, 1:18pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/6 "2014-07-27T13:18:58Z")

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Even though you have to swap ice bottles the water will create a good buffer to temp swings and keep things +/- a couple degrees, just be sure to put as much water in as you can without floating the vessel.

You can also put a t-shirt over the vessel with the ends hanging in the water and run a fan over the tub.

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**Author:** ![hjack](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/hjack/32/4692_2.png) [@hjack](https://forum.homebrewersassociation.org/u/hjack)\
**Post date:** [July 27, 2014, 4:26pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/7 "2014-07-27T16:26:28Z")

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![baregeqe.jpg](https://us1.discourse-cdn.com/brewersassociation/original/2X/f/fd35f081a831bb80b52388d759374e01e1080340.jpeg)  
I think that you will have more fun and your mind will be eased the sooner you can get to a fermentation chamber that you can control the temperature. Brew and forget.

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**Author:** ![a10t2](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/a10t2/32/6257_2.png) [@a10t2](https://forum.homebrewersassociation.org/u/a10t2)\
**Post date:** [July 27, 2014, 5:01pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/8 "2014-07-27T17:01:24Z")

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At 73°F ambient, a swamp cooler will hang out somewhere around 70°F without using any ice. With a fan and a towel or t-shirt over the fermenter, you shouldn’t have any trouble maintaining mid-60s temps without any fluctuation.

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**Author:** ![Kinetic](https://avatars.discourse-cdn.com/v4/letter/k/77aa72/32.png) [@Kinetic](https://forum.homebrewersassociation.org/u/Kinetic)\
**Post date:** [July 27, 2014, 6:36pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/9 "2014-07-27T18:36:08Z")

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> [@a10t2](#):
>
> At 73°F ambient, a swamp cooler will hang out somewhere around 70°F without using any ice. With a fan and a towel or t-shirt over the fermenter, you shouldn’t have any trouble maintaining mid-60s temps without any fluctuation.

Why don’t you like Chico?

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**Author:** ![a10t2](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/a10t2/32/6257_2.png) [@a10t2](https://forum.homebrewersassociation.org/u/a10t2)\
**Post date:** [July 27, 2014, 8:53pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/10 "2014-07-27T20:53:51Z")

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> [@Kinetic](#):
>
> Why don’t you like Chico?

You have to filter it to get bright beer. I don’t see any reason to use it when you can get a similar flavor profile out of something more flocculent.

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**Author:** ![morticaixavier](https://avatars.discourse-cdn.com/v4/letter/m/eb9ed0/32.png) [@morticaixavier](https://forum.homebrewersassociation.org/u/morticaixavier)\
**Post date:** [July 27, 2014, 11:36pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/11 "2014-07-27T23:36:49Z")

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my pedantic peak is risen.

a ‘swamp cooler’ is an evaporative cooler. you have a few inches of water in a tub with a cotton cloth hanging over the fermenter with it’s tails in the water. the cotton wicks up the water and it evaporates cooling the cloth and whatever is in it/near it 5-15 degrees below ambient depending on humidity.

you would not want to add ice to a swamp cooler because it would actually slow the evaporative process and make it less efficient.

a water bath is used mostly to stabilize fluctuating temperatures but, with the addition of heating or cooling, can be used to change the temp as well. you can add ice to drop the temp or add a fish tank heater or similar to raise the temp.

end pedantic rant.

**EDITED FOR TYPOS**

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**Author:** ![69franx](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/69franx/32/10699_2.png) [@69franx](https://forum.homebrewersassociation.org/u/69franx)\
**Post date:** [July 28, 2014, 12:25am UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/12 "2014-07-28T00:25:13Z")

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Thanks Jonathan, much better stated than I could have managed right now!

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**Author:** ![ynotbrusum](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/ynotbrusum/32/10316_2.png) [@ynotbrusum](https://forum.homebrewersassociation.org/u/ynotbrusum)\
**Post date:** [July 28, 2014, 2:18am UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/13 "2014-07-28T02:18:04Z")

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Agreed Jonathan.&nbsp; The Swamp cooler I referenced should properly have been. Water bath, but looking it up, you get both treatments referencing the swamp cooler.&nbsp; I would also mention the cool brewing bag&nbsp; - it allows a frozen water bottle arrangement without water as a temperature buffering agent.

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**Author:** ![Lazy\_Ant\_Brewing](https://avatars.discourse-cdn.com/v4/letter/l/b9bd4f/32.png) [@Lazy\_Ant\_Brewing](https://forum.homebrewersassociation.org/u/Lazy_Ant_Brewing)\
**Post date:** [July 28, 2014, 10:13am UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/14 "2014-07-28T10:13:37Z")

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What is a cool brewing bag?

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**Author:** ![ynotbrusum](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/ynotbrusum/32/10316_2.png) [@ynotbrusum](https://forum.homebrewersassociation.org/u/ynotbrusum)\
**Post date:** [July 28, 2014, 11:43am UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/15 "2014-07-28T11:43:55Z")

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I bought one after seeing it at the NHC, but anything similar would work, too:

> **[Cool Brewing - brew. ferment. keg. share. repeat.](https://www.cool-brewing.com)**
>
> One of a kind coolers designed for home beer brewing fermentation and keg serving. Beer, Kombucha, Cold Brew

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**Author:** ![ram5ey](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/ram5ey/32/13617_2.png) [@ram5ey](https://forum.homebrewersassociation.org/u/ram5ey)\
**Post date:** [July 28, 2014, 1:55pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/16 "2014-07-28T13:55:55Z")

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My first “good” beers were done in a water bath with a towel over the fermentor. I would add a frozen quart bottle every 8 to 12 hours or so and could maintain 65f pretty well. The key for you I think is timing. If you can brew early on a Saturday so that you can really manage the fermentation when it starts that evening or early Sunday then you will be keeping the ferment under control for the most vital phase. Most esters and and other off flavors are produced in the first two days of the ferment. After that you just leave it in the bath that will get you around 70. This all assuming you have weekends off…you really just need a day or so to be able to manage the start of fermentation.

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**Author:** ![majorvices](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/majorvices/32/12825_2.png) [@majorvices](https://forum.homebrewersassociation.org/u/majorvices)\
**Post date:** [July 28, 2014, 2:11pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/17 "2014-07-28T14:11:01Z")

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> [@a10t2](#):
>
> > [@Kinetic](#):
> >
> > Why don’t you like Chico?
> 
> You have to filter it to get bright beer. I don’t see any reason to use it when you can get a similar flavor profile out of something more flocculent.

I don’t use Chico a lot but when I do I can get it to drop clear with finings. Just sayin’.

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**Author:** ![ram5ey](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/ram5ey/32/13617_2.png) [@ram5ey](https://forum.homebrewersassociation.org/u/ram5ey)\
**Post date:** [July 28, 2014, 2:24pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/18 "2014-07-28T14:24:37Z")

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> [@majorvices](#):
>
> > [@a10t2](#):
> >
> > > [@Kinetic](#):
> > >
> > > Why don’t you like Chico?
> > 
> > You have to filter it to get bright beer. I don’t see any reason to use it when you can get a similar flavor profile out of something more flocculent.
> 
> I don’t use Chico a lot but when I do I can get it to drop clear with finings. Just sayin’.

I hope this discussion doesn’t put a _strain_ on your relationship…

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**Author:** ![majorvices](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/majorvices/32/12825_2.png) [@majorvices](https://forum.homebrewersassociation.org/u/majorvices)\
**Post date:** [July 28, 2014, 5:12pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/19 "2014-07-28T17:12:28Z")

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yuk yuk 😃

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**Author:** ![klickitat\_jim](https://sea1.discourse-cdn.com/brewersassociation/user_avatar/forum.homebrewersassociation.org/klickitat_jim/32/6601_2.png) [@klickitat\_jim](https://forum.homebrewersassociation.org/u/klickitat_jim)\
**Post date:** [July 28, 2014, 6:22pm UTC](https://forum.homebrewersassociation.org/t/warmer-constant-temps-vs-fluctuating-cooler-temps-for-fermenting/17254/20 "2014-07-28T18:22:30Z")

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> [@Lazy\_Ant\_Brewing](#):
>
> What is a cool brewing bag?

> [@ynotbrusum](#):
>
> I bought one after seeing it at the NHC, but anything similar would work, too:
> 
> [http://www.cool-brewing.com](http://www.cool-brewing.com)

Now see, I thought a cool brewing bag would be one made with real tree cammo material, and stainless steel rivets. Maybe some pouches for your refractometer and such. I was WAY off.

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