Wort Chilling in the Snow Took Forever!

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!

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.

wittmania said:

Is it that air, even at 0* doesn't absorb heat as well as water?

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Bingo

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.

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.

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.

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...

downinit said:

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.

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

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.

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.

When I need to chill and there's plenty of snow around, I use a big tub and a pond pump. Water and pump in the tub, and recirculate until cooled. I shovel snow into the tub to keep the chilling water cool.

I haven't done that in a while, though. I've pretty much completely converted to no-chill brewing.

cricky101 said:

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.

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I do this too I fill a 5 gal bucket up packed pretty good dump it in the sink and use my IC, cools 5 gal gal to 55 in 12 min

Just did this Wednesday. Total bummer. Forced me to buy a chiller...agood thing

jds said:

When I need to chill and there's plenty of snow around, I use a big tub and a pond pump. Water and pump in the tub, and recirculate until cooled. I shovel snow into the tub to keep the chilling water cool.

I haven't done that in a while, though. I've pretty much completely converted to no-chill brewing.

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I've done this, works really well. Saves on water to boot.

I just skimmed through this, but here we go...

If you put the pot in the snow, it will just insulate the pot, taking forever to cool.

If you leave the pot on the burner, it will take forever to cool as well (even at single digits F).

If you don't have wort chiller, your best bet is an ice bath. When you are done with plastic milk or OJ jugs, fill almost full with water, put in freezer, and reuse those in the ice bath. It will save you from buying a bunch of ice. I did this for almost a year with great results (including a 43/50 BJCP).

Even my simple Immersion chiller is fantastic. No need to make a fancy one. Buy 50' of copper coil, a garden hose to barb fitting, some vinyl tubing and hose clamps and youre good to go. Easiest thing I've ever made.

Snow is a fantastic insulator.

I boiled 4 gallons yesterday, it was about 15* outside. I took a 3gal aluminum stock pot outside with me. I put 20lbs of ice in the stock pot, and poured 2/3 the wort on it and it cooled to 70 degrees in 7-8 minutes. I then poured it back and forth into the fermenter to aerate. I took the pot back out and poured the wort back and forth very agressively from the pot to the kettle. It aerated and cooled quickly.

I fill my sink up with snow and put the pot in the sink. I have to be right there the whole time literally continuously packing snow up against the kettle. and strirring the wort. I can get it down to pitching temp in less than an hour. The trick is you need to keep melting the snow against the sides of your pot.

My advise, if you want to keep using snow, pile it in a cooler, add some rock salt (like you would an ice cream maker, and continue stirring. The salt, lowers the melting temp and actually makes a "colder" water. This "Ice" bath should cool it very quickly.

cricky101 said:

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.

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Opinion: I just used snow and liked it more than ice. We just got around 15 inches, so there is no shortage. I filled a rubbermaid tub with a 50/50 mixture of snow and water with about 15 mins left in the boil. When I got done tossed it in and stirred. I refilled twice and got it down to 60 much much faster than I ever have with ice. I think since snow are smaller particles than ice, it melts quicker (surface to volume ratio) and chills the water much faster. With floating chunks of ice, you have a lot of cold "locked up" in the cubes that is not doing its job cooling. End the end, I liked it. That being said, I have plans for a wort chiller in the near future.
Brew on.

bmud0314 said:

Opinion: I just used snow and liked it more than ice. We just got around 15 inches, so there is no shortage. I filled a rubbermaid tub with a 50/50 mixture of snow and water with about 15 mins left in the boil. When I got done tossed it in and stirred. I refilled twice and got it down to 60 much much faster than I ever have with ice. I think since snow are smaller particles than ice, it melts quicker (surface to volume ratio) and chills the water much faster. With floating chunks of ice, you have a lot of cold "locked up" in the cubes that is not doing its job cooling. End the end, I liked it. That being said, I have plans for a wort chiller in the near future.
Brew on.

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+1 on this method. I have used it since my wort chiller can only be hooked up to my garden hose which is put away for the winter. Adding snow to the slush water mixture in the rubbermaid container worked pretty well.

I just make ice baths with the snow in front of my house. It still keeps the advantage of water's excellent heat conduction while keeping freezer space open... Alternately you could just put containers of water outside the day before and freeze them to use.

I generally use an ice bath - but the last two brews were done with snow on the ground, so I used a snow bath and it did seem to get colder faster than the ice bath does.

just setting it in the snow, insulates as has been stated several times.

bmud0314 said:

Opinion: I just used snow and liked it more than ice. We just got around 15 inches, so there is no shortage. I filled a rubbermaid tub with a 50/50 mixture of snow and water with about 15 mins left in the boil. When I got done tossed it in and stirred. I refilled twice and got it down to 60 much much faster than I ever have with ice. I think since snow are smaller particles than ice, it melts quicker (surface to volume ratio) and chills the water much faster. With floating chunks of ice, you have a lot of cold "locked up" in the cubes that is not doing its job cooling. End the end, I liked it. That being said, I have plans for a wort chiller in the near future.
Brew on.

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This is the best explaination I have seen on here. I do not know why people keep fighting with putting the pot in the snow. It's grade school science. It's not going to work.
I have a chiller I made with 5/8" copper. It is the most valuable $48 I've spent in this hobby. I brewed outside yesterday while it was in the low 20's and I still used the chiller and was in the low 60's in under 10 minutes. Although, when I need to make a starter, I still use snow in the sink to cool down the 1 liter of water.

Below is the (basic) governing formula so you can see you want to maximize the temperature differential and the surface area. You would have had more luck putting it in a snow bank, feel free to borrow mine I have plenty to spare.



/nerd

Cheers,
Ben

2 words

immersion chiller.


I used snow for my first cool down and it was a waste of life 2.5-3 hours. if you stir it while chilling in the snow bank will help speed it up. Sunday I chilled 3.5 gallons with a home made 25' immersion, with nice and cold Minnesota tap water and it went from a boil to 85* in less then 12 mins. topped off with some 60* water, stirred, pitched, stirred, done

I am going to pipe in here on the snow discussion. I would agree that if you're brewing in a turkey fryer kettle, this won't work. However, my method takes about 16 minutes here in southern Indiana. I brew stovetop in two large stockpots, full boils, no water at the end. At the end of the boil, the stock pot that started a little earlier (because getting to strike temp takes time, filling takes time) is done before the other. I take it out, place it in the snow, spin one direction and stir wort in the opposite direction-then move the kettle onto new snow every couple minutes, keeping the friction going. I get done with both stock pots in about 30min. It also clears circles of ice off my walk. 2 people cut the chill time in half. Just a tad faster than chilling in an ice bath in the sink.

I toss snow in the ice bath instead... works a lot better, requires less attention, and I don't really like keeping vulnerable wort outside if I don't have to.

Come this summer, I'll probably be getting an immersion chiller though.

Same results, took nearly 3 hours to cool down.