wittmania

Recipes 

Guys,

I just brewed Yooper's DFH 60 Min IPA clone last night in my brand new 7.5 gallon stainless kettle. I got a late start and finished my boil around 10:30 PM last night. With the temperature dropping close to 0* overnight, I figured it would cool fairly quickly if I put it in my yard, which also has a couple inches of snow on it.

After waiting 3 hours and only seeing the temp drop about 40* I decided to set an alarm for 90 minutes later and went to bed. I did this several times, until the wort was finally down to about 80* some time around 4:30 AM.

I typically chill my kettle in an ice water bath in my utility sink, but the new kettle's too big for that. Chilling has taken me somewhere between 1 and 2 hours every time until now.

So, what's the deal here? Is it that the stainless is a better insulator than the thin walled, enameled canning kettle I've been using? Is it the larger volume (5+ gal. vs. 3.5~)? Is it that air, even at 0* doesn't absorb heat as well as water?

Thanks for any info you guys can provide. I can't afford too many all night brewing sessions like this one!

downinit

Recipes 

It's the volume. I too noticed how much longer a water bath takes to chill a 4 gallon brew as opposed to a 3 gallon brew. I am planning on buying an immersion chiller soon.

__________________
Primary: Wheat Porter
Secondary:
Kegged: Scottish Wee Heavy
Pale Ale

wilserbrewer

Vendor Ads 

Recipes 

Bingo

__________________
wilserbrewer BIAB Bags for sale
Expert tailor and supplier of custom sized, top quality BIAB bags, hop bags and ratchet pulleys at reasonable pricing
http://biabbags.webs.com/


CORONA MILL BUCKET SYSTEM V. 2.0

SickTransitMundus

Recipes 

It's also the contact area. Ice water cools faster because there is coolant-metal contact around the entire external area. With snow you get tiny air gaps all over the outside of the kettle, these add up and reduce the cooling rate by a lot.

For final boil volumes larger than 3 gallons, you gotta get an immersion or counterflow chiller.

Edit: What wilserbrewer said. Air is a drastically poorer insulator than water.

__________________
Fermenting: Gerboise Bleue Farmhouse Ale. Ivy Mike Citra-Victory Pale Ale.
Kegged: Colonized By Wankers Wee Heavy. Spanked By Leviathan Barleywine. Green Hell Double IPA.
On tap: Castle Bravo American Stout. Silence of the Chavs Robust Porter. Smell the Glove Bretted Quad.
Gallons in 2011: 145 and counting.

gingerdawg

Recipes 

Snow is a great insulator. That's why igloos work.
When you put the kettle in the snow, it quickly melts the snow a fraction of an inch back away from contacting the pot. After that, the snow is actually helping keep the pot warm. If use snow to cool, put it in a water bath or keep moving the pot/snow to keep it in contact with the pot.

TheSeether

Recipes 

Air has a very low heat transfer capacity. Snow has a fairly high insulation capacity as well. Avalanche survivors survive thanks to a blanket of snow keeping them insulated until they are found.

You will get the best external chill by circulating cold water against the metal brew kettle. You can add salt to ice water to drop the freezing point and achieve a colder bath. The only other method of increasing heat dissipation would be to somehow extend the surface area of the kettle with a metal enclosure that incorporates heat fins that are subjected to circulating cold water.

High metal surface area coupled with circulating cold water is about the most efficient heat transfer available in the kitchen on the cheap. You could always look at employing liquids with lower freezing points and higher thermal transfer capacity such as glycol based solutions but that gets messy and expensive. An active submersible wort chiller (or counterflow) presents the highest degree of thermal transfer efficiency for the dollar.

Lacking a submersible chiller and an appropriately sized sink I would strongly consider using a bathtub to make the cold water bath. This certainly will not be the most efficient in terms of water or ice use but the large surface area will provide a better transfer and a better ability to provide a higher degree of circulation. There is the whole issue of transferring hot wort to a bathtub to contend with.

r8rphan

Recipes 

I tried the chilling in the snow method on my first ever batch... and that was with 2 feet of snow out there... Eventually brought it back in and chilled it in the sink.. never tried the snow theory again... doesn't work...

A few batches later I made an IC.. when I switched to 10G batches, I then hated the IC, so now it's a custom made flat all copper CFC... finally happy...

__________________
"DOH!"
Homer Simpson

"Beer is living proof that God loves us, and wants us to be happy."
(possibly said by) Ben Franklin (maybe)

Quote:

Originally Posted by arturo7 Damn, where's my arm?.

"You can pick your nose, and you can pick your friends... but you can't pick your friends nose!"
George Carlin

MeatyPortion

Recipes 

Ditto. I did a stove top AG last week and buying an immersion chiller is no longer an option.

__________________
Primary
mila jovovich
Bottled
zilch
Kegged
Milk Chocolate Fusion Stout

Ph'nglui mglw'nafh Cthulhu R'lyeh wgah'nagl fhtagn

cricky101

Recipes 

I used snow once, but had my kettle in a water bath in the sink and dumped snow into the water to cool it. Worked OK, but it melted very fast and had to be replenished often. It was a lot less work buying a bag of ice at the store and using that in the water bath.

TheSeether

Recipes 

It's even less work to freeze appropriately sized bags or cups of ice in your home freezer if you can spare the space and can think a day ahead.