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Cool Brewing Fermentation Cooler Bag
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Control your fermentation temperatures with Cool Brewing's simple, yet innovative, insulated fermentation bag. This is the 2nd generation Cool Brew bag, which has made cold fermentations even easier!  Fermenting your homebrew at the right temperature is one of the critical factors in making good beer. Let the temperature get too warm, and your beer will taste 'rough' as the soft malt and vibrant hop flavors dissapear!  Typically an advanced homebrewer would want to get a spare refrigerator or even a MoreBeer! Cooled Conical to control fermentation temperatures, both those options either take up a lot of space or can cost a fair amount of money.  The Cool Brewing Bag allows the apartment brewer, those who have space constraints, or the brewer on a budget a great option to control fermentation temperature and make great beer.

Cool Brewing's Fermentation Cooler is designed specifically to accommodate standard 6.5, 6 or 5 gallon fermenter. You freeze a 2 liter soda bottle with water, or similar, and place in the fermentation bag with your fermenting carboy.  Also works great with the Ss BrewTech Brew Buckets!

The typical desired ale fermentation range is on average around 62-72° F.  For a typical 5 gallon batch (1) frozen 2-liter bottle should lower wort temperature around 5 degrees, while using (2) 2-liter bottles will lower wort temperature around 11 degrees for 24-36 hours. Of course your exact results might vary but you can adjust the amount of ice you use as you go. The manufacturer has found they can cool the wort temperature up to around a 30-35° drop from ambient room temperature.  On the flipside, add a Fermwrap and temperature controller to the setup, and you've got a heated fermentation temperature accurate to within 1° F!

The Cool Brewing Fermentation Cooler is sealed, insulated and 100% waterproof so it will efficiently and neatly keep your temperatures in check.  When you’re done, the Cool Brewing Fermentation Cooler easily folds up for storage until the next brew day!

 Cool Brew Features:

  • Up to twice as efficient and cleaner then homemade swamp coolers
  • Much less expensive than custom kegorator or keezer set up's that cost $100's of dollars.
  • Cool Brewing Cooler will work with multiple sized fermenters.
  • 100% waterproof so will not leave condensation.
  • It folds up for easy storage when not in use or travel.
  • Will work great in condos and warm climates where you need a swamp cooler even for Ale’s!
  • Contains the mess of any fermentation blowouts
  • Inner dimensions: 20.5"D x 25.5"H
Item # FE530
Shipping Eligible for Free Shipping Program
Availability California - In Stock
Pennsylvania - In Stock
Weight 5LBS
Community Q&A

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Why did you choose this?
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Easy way to better control ale fermentation
George S on Sep 3, 2018
My Nephew referred it to me after I complained to him about my fermentation woes living in SoCal. He LOVES it!
Scott G on Aug 25, 2018
Easy way to better control ale fermentation
George S on Sep 3, 2018
For apartment brewing
katherine c on Sep 1, 2018
My Nephew referred it to me after I complained to him about my fermentation woes living in SoCal. He LOVES it!
Scott G on Aug 25, 2018
Leonard B on Aug 23, 2018
Hoping to control my fermentation better. Do not have the space for another fridge.
Gregory B on Aug 21, 2018
Need to better control temp in summer
Alan L on Jun 26, 2018
Summers too hot
joel h on Jun 4, 2018
Need to cool fermentation
Allison R on May 23, 2018
Live in florida and needed something easy and doesn't take up much room to ferment my homebrew
David O on May 10, 2018
summer brewing, limiting esters, etc
Anthony D on May 1, 2018
I'm not ready to upgrade to an extra fridge.
David P on Apr 19, 2018
cool wine fermentation to 60 degrees
JEFFREY S M on Apr 16, 2018
Hopefully better than my failed homemade one
John S on Apr 5, 2018
It was highly recommended by a home brewer.
carlos t on Feb 19, 2018
california weather
Jeff I on Jan 22, 2018
For apartment brewing
katherine c on Sep 1, 2018
Leonard B on Aug 23, 2018

4.6 / 5.0
40 Reviews
5 Stars
4 Stars
3 Stars
2 Stars
1 Star
Very nice
I'm using it to keep 3 1-gallon carboys cool and dark.
July 12, 2018
4 months ago
It's been holding temperature good
May 31, 2018
5 months ago
Cooler delivered as described. Can't wait to use on my next brew.
May 18, 2018
6 months ago
Great product!
Love this thing! Kept my beer between 38 and 40 degrees for a week which allowed me to clear it beautifully with gelatin. Can’t wait to make a Vienna lager!
By switching out frozen bottles every 24 hours, kept beer between 38 and 40 degrees for a week.
By switching out frozen bottles every 24 hours, kept beer between 38 and 40 degrees for a week.
May 2, 2018
6 months ago
Great so far
Only one use but it maintained between 10 and 13 degree drop from ambient air temp. That was with just one half gallon milk jug frozen with salt water.
In fairness it was only a two gallon batch so it should have performed well.
Very rarely do I recommend something but this product is good enough to earn my endorsement.
April 23, 2018
7 months ago
Great bag.
It works. Helps avoid volcanoes and keeps temp where it should be.
February 8, 2018
10 months ago
Great Insulation
Works as it should! Lowers my ambient temps by 10-15 degrees. I even uses it in addition to a recirculating cooling jacket to keep a keg cold and force carb before I had my keezer built. Its water proof too!
January 23, 2018
10 months ago
I have been using this ferm bag for 2.5 years after using a tote with iced bottles to control temp. Initially, I filled the ferm bag with water and added iced bottles. That caused rapid cooling and some buffering of temp changes. It also cause condensation on the outside that was not desirable when sitting on carpet. Over time, I have stopped the use of water, but I found it less efficient due to an air gap between the iced bottles and carboy.

Currently, I add bubble wrap around the inside wall of the ferm bag and between carboy and bag's top. This keeps bottles tight against carboy and significantly increases efficiency.

I sit the bag on a few wood slats to avoid condescension issues. I also cold crash using the bag. With the addition of a bedspread on the outside, I can reach 36 degrees. It is a good product to start with and can be improved using additional insulation.
October 20, 2017
Perfect when using with Speidel Plastic Fermenter - 30L (7.9 gal)
So yea, works great here in Sacramento during the summer, swapping out frozen 2L bottles. Just like everyone else who loves this.

What I really like is that it is perfect with the Speidel Plastic Fermenter - 30L (7.9 gal). The height of the Speidel airlock is about the same height as the zipper on the Cool Brewing bag. The top of the airlock is actually a cap actually "floats" on top. When I zip the Cool Brewing bag shut, it pushes the air lock cap down a bit, making it harder for the gas to release.

This produces a louder pop/gurgle when the pressure equalizes and the gas eventually escapes. I find this beneficial, especially when fermentation slows. I know it's still going instead of trying to determine if it's just slow, or has stopped all together.

Before using the bag, gas still being produced would just seep slower, and silently without the force of the zipped bag pressing the airlock cap down. Using the bag, two weeks into fermentation, periodically I can still hear a "pop" (longer between intervals, naturally) telling me it's still going.
September 16, 2016
Was skeptical. Dual use giant cooler.
I use ferment buckets (FE361 -- tap the lids down with a mallet btw) for 4 week ale primary and there is plenty of room for ice around the sides and the top -- the insulated bag is huge. I could probably pack 20+ liters of ice around my buckets if needed. About 1 L of ice per -1F. I use an Oneida candy thermometer to help keep my temperature in range.

April 23, 2016