Wet Towel + Hot Kettle = Faster Cooling?

[HopSing]

Does anyone wrap their brew kettle with a wet towel after flame out to take advantage of evaporative cooling? Seems like it would work in principle and help the immersion chiller bring down the wort to pitching temp quicker.

I'm planning a brew session this weekend and thought of giving it a try unless someone feels like this is a bad idea (I'm hoping it would not act like an insulator and prolong the cooling).

~HopSing.

 

[porterpounder]

Pretty sure with water it won't cool evaporate quickly enough to make a difference, but anything is worth trying once. Maybe soaked in subbing alcohol, but with the flame very much off and the pot luke-warm.

 

[unviewtiful]

I guarantee it will work, but the towel will get really hot really fast. Though after a certain point, it will likely slow down cooling by acting like an insulator, as you say. Just use it to soak up some heat and then remove it from the pot.

You could also mist the outside of the pot for the same effect with less thermal mass. Evaporative cooling only works when there is enough airflow to make the water evaporate, meaning a thinner layer of water is most effective.

I should add though that it's probably more effort than it's worth for a minimal boost in cooling speed.

 

[HopSing]

Thanks for the input. I was planning to keep the towel wet with a pitcher of ice water and perhaps a fan blowing on it. I'm assuming as long as the towel stays wet and the air temp is lower than the wort temp, I should gain something, no?

Sounds like I might need to make 2 batches this weekend to test the theory. The things I do for science.

~HopSing.

 

[JohnSand]

I have tried, keeping it wet with the cooling water outflow. Since it gets hot, it is absorbing heat. How much, I cannot measure. I just used an old tee shirt.

 

[HopSing]

Right now my stainless I.C. is taking about 37 minutes to bring me down to 68* F. Even if I can shave 10 minutes off that time, I'd be happy. Good idea for the tee shirt. It will be less likely to act as an insulator.

~HopSing.

 

[normonster]

...
I should add though that it's probably more effort than it's worth for a minimal boost in cooling speed.

For me it might just be the ticket to a shorter brewday. I can't chill in one pass so I end up chilling my entire boil kettle....I'm going to try this.

Thanks OP. Sometimes the most simple ideas are gold. If I can even get a 15 minute dent in cooling I'll be stoked.

 

[madscientist451]

Get a plastic tub big enough to hold your brew pot and add cold water and ice. When you want to chill, put the IC in the brewpot then the brewpot in the tub w/ice water. This should cut some time off, although eventually the tub water will get warm and it would be better to pull the pot out. I'm skeptical the wet towel will make any difference at all.
The warm water in the tub can be used to wash up your brew pot.
Another idea is to run your chiller water through an ice bath so its colder before it goes through the IC.

 

[Jtk78]

...
Another idea is to run your chiller water through an ice bath so its colder before it goes through the IC.

This is what I do. I made a coil out of 25' of refrigerant copper on put it in a cooler with ice and water. This gets hooked up with vynal hoses before going to my immersion chiller. I'm usually about 70 in 20-25 minutes. I also remove my kettle from the burner, which I feel helps. I put the kettle on a flat bed cart and wheel it over to the sink area. Gets cooled right on the cart.

Although the spraying outside of kettle method may get added to my routine.

 

[RM-MN]

Get a plastic tub big enough to hold your brew pot and add cold water and ice. When you want to chill, put the IC in the brewpot then the brewpot in the tub w/ice water. This should cut some time off, although eventually the tub water will get warm and it would be better to pull the pot out. I'm skeptical the wet towel will make any difference at all.
The warm water in the tub can be used to wash up your brew pot.
Another idea is to run your chiller water through an ice bath so its colder before it goes through the IC.

Your IC will be pretty efficient at removing heat while the wort is hot but will lose some of that efficiency as the wort gets cooler. That is when I'd put the pot into the tub of water to help speed the cooling.

If you have plenty of ice, put the pot into the tub of ice water immediately and it will speed up the cooling.

 

[crane]

I heated my HLT up 10+ degrees too much one brew day and needed to cool it down before doughing in. I use RO water with mineral additions so I didn't want to dilute with cool water. I tried this method for 10-15 min before giving up. I dropped only a couple degrees in the 10 gallons of water in the HLT. Taking the lid off and stirring brought it down faster. The problem is that the towel will heat up so quickly. You also need some pressure to hold it on to the side of the kettle for good heat transfer. You would need a lot of water to keep pouring over the towel/t-shirt to keep it from getting hot.

 

[HopSing]

Update. I brewed two batches this weekend to test the evaporative cooling theory. While not the caliber of an xBmt (love this site http://brulosophy.com/exbeeriments/) I do think it is an interesting result.

Both batches had the same volume of wort at flame out (6.25 gallons). Both batches had a similar grain bill with similar OG. Air temp was within 1.5 degrees F (61.7 vs 60.2). Same equipment. Process was to use an immersion chiller with 55.2 F degree tap water for 20 minutes, then switch to a recirculating pump in a bucket with ice. Same volume of ice was used in both batches. Without the wet towel wrap, the wort cooled to 67 F degrees in 48 minutes. With the wrap, it cooled in 38 minutes, which is a 21% gain. I also had 2 small 80mm USB fans blowing on the wet wrap. These fans are not very powerful, but the side of the kettle with the fans felt much cooler than the other side, so I think using a larger fan could reduce the cooling time. I also had a lot more ice left over in the recirculation bucket after the 67 F degree temp was reached with the wet wrap, so if I switch from tap water to recirculation sooner it might also drive down this time.

Here’s a picture of the wrapped kettle. Yes, I did get permission from SWMBO to cut this beach towel:

 

[JohnSand]

Thanks for the report. That is a significant difference.