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January 26, 2009

Banana hammer cold

Posted: 11:13 AM ET

From the West, to Midwest, the Northeast to parts of the South it's cold. I mean banana hammer cold. Never seen that measurement on the thermostat? Well, you've obviously never been to Minnesota in the winter.

How cold is it? Cold enough to turn a banana into a hammer. Photo: Getty Images

Meteorologist Jonathan Yuhas from Minneapolis affiliate KARE showed CNN's Heidi Collins what last week's subzero temperatures could do to everyday items.

According to KARE, on January 15 it was negative 21 degrees Fahrenheit, factoring in the windchill. That's just 17 degrees warmer than the freezing point for liquid mercury. And one more reason I will not visit Minnesota in the winter.

Now, bubbles don't shatter and hot water doesn't turn to a frozen cloud in normal weather conditions. It has to be cold. Very cold. Cold enough to pass those items' freezing limit.

Generally defined, a freezing point is the temperature where the liquid state of a particular compound freezes to form a solid. For freshwater, this temperature is 32 degrees Fahrenheit. For a banana or other foods, it depends.

A work by Dr. Richard W. Hartel of the University of Wisconsin-Madison states that "foods are mixtures of various ingredients, some of which affect phase behavior of water.." Meaning, since foods contain sugars, salts, proteins, fats, flavors, etc., there is no one broadly defined freezing point for food. For fruits, Hartel gave a general freezing point between 30.4 – 27.1 degrees Fahrenheit.

Hartel also gave the average freezing points of some other food categories:

Vegetables: 30.6 – 26.7 F
Meat: 28.9 – 28.0 F
Egg: 31 F
Milk: 31 F

Ice, snow, banana hammers, frozen bubbles–at 21 below, they're all the same. Frozen.

According to, which is my authority on everything bubble-related, it is possible to freeze bubbles. Our iReporters also proved us that. But once the bubble freezes, it's only a matter of time before they shatter.

This is because when a bubble is blown into subzero temperatures, the warm air inside the bubble quickly contracts. The volume of air becomes lower, and the bubble crumples under its own weight.

CNN iReporters also got in on the action, freezing everything from food to flash-freezing hot water. Others are using the freezing weather to go green. iReporter Kyle Aevermann shared his use of a "natural freezer" in Chicago's subzero temperatures.

The Food and Safety Inspection Service, a branch of the USDA, recommends against doing that, however. The agency's Web site Fact Sheet states: "When it is freezing outside and there is snow on the ground, it seems like a good place to keep food until the power comes on; however, frozen food can thaw if it is exposed to the sun's rays even when the temperature is very cold. Refrigerated food may become too warm and foodborne bacteria could grow. The outside temperature could vary hour by hour and the temperature outside will not protect refrigerated and frozen food."

So besides food, what else have you found freezing point for? Wet laundry? An umbrella? We want to know. Send in your iReports. Leave a comment.

- Brandon Ancil,

Filed under: science • Weather

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Casey   January 26th, 2009 12:25 pm ET

What the heck is a banana hammer? I assume it's when a banana gets frozen and can be used as a hammer, but I'm not sure. YOU NEVER SAY!

Franko   January 26th, 2009 2:22 pm ET

Kill the Evil Molecule Kill
Plummeting US into an Ice Age

Quick ObeWan, Gore, and other Noblers than US, advising
Before it is too late, and the Ice Bears eat US all !

Nunya   January 26th, 2009 2:30 pm ET

"For fruits, Hartel gave a general freezing point between 30.4 – 27.1 degrees Celsius.
Vegetables: 30.6 – 26.7 Celsius
Meat: 28.9 – 28.0 Celsius
Egg: 31 Celsius
Milk: 31 Celsius"

I guarantee you, at these temperature ranges, these things are *not* frozen. Water freezes at zero Celsius, and the freezing temperatures of these other items would be even lower. All those Celsius temperatures in the table listing freezing points should be labeled Fahrenheit, not Celsius...

Franko   January 26th, 2009 2:55 pm ET

Propane boils at −42.09 °C
To cook breakfast, warm the propane tank outside, with a blowtorch

But that emits evil CO2 - cooling the Earth more, endlessly more Increase CO2 Taxation Credits, more and more

Sequister the Evil Cooling Devil CO2
Increrase Financial Liquidity, Produce Jobs, to warm US up

Joel   January 26th, 2009 3:17 pm ET

Yeah, I think you have your unit mixed up here.

Franko   January 27th, 2009 1:14 am ET

Can we genetically engineer trees that produce Ice Age Fruits ?
Perhaps plants that use an antifreeze as the working fluid
Ethanol is liquid between −114.3 °C and 78.4 °C

We could really save the economy - Fruit of Vitamin and Vice
And squeeze the Ice Oranges, to fill up your car ?

BC   January 28th, 2009 8:57 am ET

This is the same temp that algores brain froze at and never regained function

Wisdom   January 28th, 2009 10:02 am ET

This Global Warming must be stopped... oh wait?

Franko   January 28th, 2009 12:49 pm ET

Ethanol is bacteria produced - "$1 a Gallon, and Without Corn"
From the Bacteria; Spice the Alcohol producing genes to Bananas
Then Oranges, Apples, Pigs, and Cows

People are only a little Ethanol tolerant
Not less than 2 beer before you drive,
But an easier to count Ethanol Apple

Pete   January 28th, 2009 1:50 pm ET

Everything is relative. Yes, this year and last year have seen colder than average winters, but let us not forget that the average is a rolling average of the last 20 years. If you were to go back to the 70's and compare this year to the average of that time, I think you would find that this year's temps are about normal for that time.and maybe even a little above average. I seem to remember Januaries in Wisconsin where the temp would not rise above 0F for a week or more at a time. I haven't seen a winter like that since 1995.

Franko   January 28th, 2009 2:48 pm ET

With the coming IceAge, can we adapt the Flora and Fauna ?
Water freezes, inconveniently, at 273.15°K
Antifreeze ideas – spike your warm thermos of tea with Ethanol
Melt your driveway with rocksalt - synthetic oil for your car.

"Freeman Dyson has proposed the creation of a Dyson tree,
a genetically-engineered plant capable of growing on a comet"
Just think, the Eskimo would not have to kill the cute IceBears for food
Pick the IceBananas, eat IceTomatoes, - the benefits are endless

Ken in Dallas   January 28th, 2009 5:46 pm ET

Well, if bubblemania told you that frozen bubbles collapse of their own weight, they need to redo some experiments. What crushes your frozen bubbles is the weight of the atmosphere, i.e., ambient air pressure, which is reduced inside the bubble by contraction of the air inside it.

You did leave out the expository reference to Yhuas' bammer experiment, by the way. I saw it, but I can understand the WTH reaction from posters who didn't.

Franko   January 30th, 2009 11:33 am ET

"solutions to the climate crisis" (Crisis of Runaway Global Prosperity)
Eating frozen bananas in the IceAge ?

CO2 enhances radiation on top - Cools
CO2, on the bottom, traps heat

The extra Heat on the bottom increases surface evaporation and wind speed, which distributes H2O and Heat - The overall Average Surface Tempertature change to CO2 doubling may be close to Zero - However, extra H2O and CO2 happier become the plants and the plant eating people.

The plan of ObeWan to reduce CO2,
Will have the effect of starving the plants, and his relatives in Africa

S Callahan   January 30th, 2009 5:46 pm ET

My day always ends with a smile when I read Franko's comments!

This recent 'freeze' weather doesn't seem so different than the weather in the 50 and 60's.....the only difference I see is the profiting off of nature.

Franko   January 31st, 2009 1:30 am ET

May the smile of reality be with S Callahan
The Climate Hypnosis is scary (feel the warmth of the taxing frostbite)
ObeWan should read up on ancient Chinese Culture
The Jade Emperor, 玉帝, wins without really doing anything
"knows all aspects of The Way (DAO) and its Principle of Least Action, making Heaven's regime the ultimate example of a do-nothing policy"

Aussie Jane   February 2nd, 2009 8:00 pm ET

Unleaded gasoline will freeze between -120F and -240F depending on the chemical mixture; i.e. additives, detergents, ethanol, etc.

refinance   May 9th, 2009 8:14 am ET

what is money? 🙂

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Hey guys do you know it takes a temperature of 31F to freeze an egg.

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