Any ice chemistry/physics experts out there?

[tubber]

I've brought dressed fish home for processing on flake salt ice many times with no problems. I put 5 sockeyes in a cooler yesterday belly iced and covered in about 5 bags of gas station ice cubes, and this morning they were frozen. I thought salt ice was colder, yet that's never happened to me before.
By the way, the guys at the Lonsdale fish market gave my wife the numbers of their salt ice suppliers and when she called, one was in French Creek and the other was in Victoria. WTF?

 

[lordofthesprings]

hmm interesting you'd think there would be salt ice in steveston ?- and i guess you had the ratio of fish to ice just right to do that I'm just a drywaller though ha

 

[Fish Assassin]

I have seen a mixture of ice and sea water freeze fresh herring.

And I know a mixture of ice, rock salt and sea water can freeze a chinook.

 

[SpringVelocity]

The ratio of salt may have been too high. I am not going to confuse you but mathematically it changes the melting point of water, and also once frozen allow the molecules to essentially be more free to move.... That allows it to pull Kinetic energy (KE=1/2*m*V^2 )from the environment. Your frozen fish is the result of this energy transfer... Think of it as actually pulling the heat away from whatever it contacts. Higher the salt the more those molecules can move and pull in heat. Its obvious there is a right mixture. Non confusing response way too much salt or too much volume of ice.

Here is also description I found on net:

Once salt comes into contact with water, NaCl would split into Na(+) and Cl(-). Since these atoms have charges, they "tug" at individual water molecules. This makes the water less rigid and separate from each other. Since they are less rigid, the water molecules are free to move around. This movement is kinetic energy, which is measured by temperature. Due to the law of conservation of energy, the kinetic energy of the water can't just appear, it has to come from it's surroundings. So the air and objects near the ice/salt solution would transfer their heat to the ice/salt. More powerful salt, like CaCl2 works better than regular salt because when it touches water, it splits into three atoms: Ca(+2), Cl(-), and Cl(-). The extra atoms mean more force when they "tug" at water molecules.

 

[Fish Assassin]

Now that was a test of my last brain cell..............

 

[Sr SQ]

I've brought dressed fish home for processing on flake salt ice many times with no problems. I put 5 sockeyes in a cooler yesterday belly iced and covered in about 5 bags of gas station ice cubes, and this morning they were frozen. I thought salt ice was colder, yet that's never happened to me before.
By the way, the guys at the Lonsdale fish market gave my wife the numbers of their salt ice suppliers and when she called, one was in French Creek and the other was in Victoria. WTF?

SV is right…….best way I heard this explained was.
Your cooler was able to keep the ice in a solid state but regular ice wont cool your fish as much as salt ice because salt ice will turn into a liquid about -1-2c so your fish will be immersed in a freezing liquid not covered in a freezing bunch of solid cubes, the liquid will pull more heat from your fish than the solid will.
In the slightly thawed slurry of salt ice your fish could freeze because of the temp of the slurry is actually lower than 0c
Not sure if that helps?

 

[Resinrider]

Remember there is no such thing as cold... only the absence of heat. When Ice changes from a solid to a liquid state, It's ability to absorb heat increases dramatically. Since the regular ice melts much sooner and faster than salt ice, It absorbed more heat faster from your fish.

 

[tubber]

Non confusing response way too much salt or too much volume of ice.

I didn't add salt so it must have been too much ice, especially when we threw two unopened bags on top of the fish/cubes. Anyway, they were not frozen when I opened the coolers this morning, and are in the vac bags and freezer and look good. Lots of lice on these sox.

 

[mbowers]

The most important thing is how cold was the ice you added. Salt ice and freshwater ice out of the same freezer have nearly the same amount of cooling potential. Sounds like you put a lot of very cold ice straight from the freezer on top of already cold fish and that will freeze them. 5 bags of cold -20 C freshwater ice can freeze a couple of cold fish while even 500 bags of -4 C salt ice can't.. For cooling fish fast a brine is good but the minimum temperature of the fish is determined by how much and what temperature ice, not by how salty it is.

 

[tubber]

The most important thing is how cold was the ice you added. Salt ice and freshwater ice out of the same freezer have nearly the same amount of cooling potential. Sounds like you put a lot of very cold ice straight from the freezer on top of already cold fish and that will freeze them. 5 bags of cold -20 C freshwater ice can freeze a couple of cold fish while even 500 bags of -4 C salt ice can't.. For cooling fish fast a brine is good but the minimum temperature of the fish is determined by how much and what temperature ice, not by how salty it is.

That's right, too much new ice pretty much straight from the gas station onto the already cold fish. I'm familiar with the fact that the ice in my drink is about 0 Celsius, but did not realize that the ice in a -20 freezer will be, well, -20 after and for a while. Also leaves ice cube shaped dents on the fish.

 

[Jeep09]

He had me at salt ice..