Keeping Fermentation Temps Down

[Savage06]

So I am still struggling keeping fermentation temps down in the 60s. I keep floating up a bit warm and I am getting a bit of twang that I no longer want.

I ferment in buckets or a 6gallon better bottle. What I have been doing is putting the carboy in a large storage container and pouring cold water up to the beer line or above. And occasional putting a tshirt over the top. Though through testing I have not seen the tshirt do much good.

The issue I have is that this is a LARGE volume of water so it is very hard to move the temp down even with a few frozen water bottles and the water will creep up to about 70 meaning the beer temp is probably high 70s. Also the water gets fairly gross after 7-10 days and harboring bacteria right next to the beer probably isn't great

I would love to get a fermentation fridge with temp controller but spending 100-300 and the space to plug it in isn't very practical as of now.

I did buy a 10g round cooler which will fit the carboys and buckets. My thought is that since the vessel is insulated it will hold lower temps better for longer with less ice.

Though the challenge I see is there is very little space for water around the vessel so not sure if this is better or worse.

Has anybody tired this and had success. I need to cut a hole in the lid of the cooler to manage this and would love to get some feedback before i start pulling it apart

I figured if this doesn't work i have a solid mash tun ready to go with a few fittings.

 

[Yooper]

I use a 60 quart Igloo (it's big) and it has wheels. I took off the hollow plastic lid and made a new lid out of four layers of foam insulation.

I float a floating thermometer in there, add 2L frozen soda bottles as needed, and a splash of bleach into the water bath. It works great.

Here's a photo:

 

[BuddyWeiser]

Never tried using a cooler, but I would think that less water would equal easier to change the ambient temp inside the cooler. For example, I have better luck using coolers (in general/not brewing related) if I keep all of the water drained. As you mentioned, the water can melt the ice right away without really lowering the temp. By keeping the water drained and using just air and ice, my coolers seem to stay colder longer. I think this is largely in part due to the insulating effects of sealed-in air (which is how styrofoam and double pane windows work).

As for the t-shirt trick, I think it's mainly for evaporation type cooling. If the water level is only a few of inches high and just the bottom of the shirt is in water, then the fabric of the shirt pulls water up along the sides where it can be evaporated to cool the fermenter. I have had good luck with setting the fermenter in a shallow tub of water, pulling the t-shirt tight over the top using clips and making sure the entire bottom of the shirt is in water, and then pointing a fan directly at it. I've even added ice cubes to the water and stuffed them inbetween the shirt and the fermenter.

 

[Savage06]

What type of insulation is that and did you have to glue it together?

I use a 60 quart Igloo (it's big) and it has wheels. I took off the hollow plastic lid and made a new lid out of four layers of foam insulation.

I float a floating thermometer in there, add 2L frozen soda bottles as needed, and a splash of bleach into the water bath. It works great.

Here's a photo:

 

[lactardjosh]

I use the classic red Igloo cooler which is not as big as Yooper's. I use old large plastic bottles with frozen water to keep the temps down. With one large bottle I can keep the temps down around 61° if I change the bottles out every 12 hours or so. With four large bottles in the cooler, I can get the water temp down to at least 39°. It might go lower but I had forgotten to take the other three bottles out one time when I was trying to rush getting the wort down to 60°.

I've got 3 layers of 1/2" Styrofoam as the top. It only covers up to the top of the wort in the carboy, but I put a towel over the top to protect from light.

 

[itsernst]

I use the classic red Igloo cooler which is not as big as Yooper's. I use old large plastic bottles with frozen water to keep the temps down. With one large bottle I can keep the temps down around 61° if I change the bottles out every 12 hours or so. With four large bottles in the cooler, I can get the water temp down to at least 39°. It might go lower but I had forgotten to take the other three bottles out one time when I was trying to rush getting the wort down to 60°.

I've got 3 layers of 1/2" Styrofoam as the top. It only covers up to the top of the wort in the carboy, but I put a towel over the top to protect from light.

Do you think a swamp cooler could produce a quality lager? I am skeptical based on what i read and really want to try brewing a lager.

 

[lactardjosh]

Do you think a swamp cooler could produce a quality lager? I am skeptical based on what i read and really want to try brewing a lager.

Lagering with a swamp cooler is a long term commitment to changing out frozen water bottles at least twice a day. I was surprised when the water temps got that low, but it'd be difficult to keep them that low and steady for the lagering period.

 

[CarboyBoy]

The issue I have is that this is a LARGE volume of water so it is very hard to move the temp down even with a few frozen water bottles and the water will creep up to about 70 meaning the beer temp is probably high 70s. Also the water gets fairly gross after 7-10 days and harboring bacteria right next to the beer probably isn't great

You may not be in as bad a shape as you think. The 5-10° differential you hear about is between ambient temp and beer temp. If you have water up to beer level, you're only looking at a degree or so of difference between the water bath temp and the beer temp.

If you're concerned about the quality of the extended water bath, you can remove your fermenter from the water after about 5-7 days. After primary fermentation has ended, you don't need to be as concerned about temp control.

 

[Yooper]

What type of insulation is that and did you have to glue it together?

It's four layers of foam insulation from Home Depot- I bought one big sheet (it's for houses), which I think is 4X8 and cut it to fit.

Do you think a swamp cooler could produce a quality lager? I am skeptical based on what i read and really want to try brewing a lager.

I can do it! BUT, in the winter, my basement has an ambient of 48 degrees, which is perfect for fermentation. I ferment at 50 degrees (a couple of degrees warmer than ambient is fine- I keep it up off of the basement floor, and it settles right at 50 degrees), bring it upstairs for the diacetyl rest, and then rack when fermentation is finished and begin lagering. I then add the carboy and frozen water bottles and water to the cooler, cover it up and hold it there for 10 weeks or so, just changing out water bottles every day or so. I lager at 34 degrees that way.

 

[itsernst]

It's four layers of foam insulation from Home Depot- I bought one big sheet (it's for houses), which I think is 4X8 and cut it to fit.



I can do it! BUT, in the winter, my basement has an ambient of 48 degrees, which is perfect for fermentation. I ferment at 50 degrees (a couple of degrees warmer than ambient is fine- I keep it up off of the basement floor, and it settles right at 50 degrees), bring it upstairs for the diacetyl rest, and then rack when fermentation is finished and begin lagering. I then add the carboy and frozen water bottles and water to the cooler, cover it up and hold it there for 10 weeks or so, just changing out water bottles every day or so. I lager at 34 degrees that way.

First time I can say I have been envious of a person from Michigan in the winter.

Lagering with a swamp cooler is a long term commitment to changing out frozen water bottles at least twice a day. I was surprised when the water temps got that low, but it'd be difficult to keep them that low and steady for the lagering period.

So what do you think about the Cool Brewing fermenter bag? In San Diego, it has been pretty warm and my fermentation temps are on the high side (75 degrees and as high as 77). I was using Safale 05, so i think it will be alright in the end, but I really want to lower temps to see how big of a difference it could make. Even further, if I could lager without making the girlfriend mad by purchasing additional things to clutter the kitchen, I am all for it.

https://www.cool-brewing.com

 

[Yooper]

First time I can say I have been envious of a person from Michigan in the winter.



So what do you think about the Cool Brewing fermenter bag? In San Diego, it has been pretty warm and my fermentation temps are on the high side (75 degrees and as high as 77). I was using Safale 05, so i think it will be alright in the end, but I really want to lower temps to see how big of a difference it could make. Even further, if I could lager without making the girlfriend mad by purchasing additional things to clutter the kitchen, I am all for it.

https://www.cool-brewing.com

I have one. I've only used it twice, and the ambient was only in the mid 70s, so I don't have much experience.

My experience so far is "it's ok". It's really, really, really big. I think that is a minus for me, as it seems like 7 ice blocks are lost in there. I'd rather have it fit smaller, and use less water/ice. But it seems to maintain the temperature pretty well once settled.

I think if it was smaller, I'd like it more. Or bigger, so I could put 2 fermenters in one. But it's so large it feels like it would take more mass inside to raise or drop the temperature (a larger water bath, for example).

 

[david_42]

the water will creep up to about 70 meaning the beer temp is probably high 70s

Not the case. Four or five years back several people ran tests comparing the temperatures inside and outside of a 5 gallon fermenter, water bath or air cooled. The delta is within the measurement error. TEN gallons of fermenting beer will have a 3-4F differential. Anything bigger and you need active cooling.