Why isn’t there a reverse microwave oven to cool food quickly?

Answer 1

There is -- call it a "sonic refrigerator".

Answer 2

Heating the food relies on the energy transferred when the RF energy from the microwave oven gets translated into molecular kinetic energy in the water molecules in the food. Also is some interacton with fat and sugar in the food too.

The heat will escape the food as infrared energy and currently we have no way to do this except by allowing the heat to flow from a region of higher temperature to a region of lower temperature.

If the food just sits there the air nearby will be warmed and the cooling effect is reduced since the heat transfer is proportional to the temperature difference. So what you need to do is to remove the warm air that is next to the food and replace it with cooler air. Imagine a convection oven but you exhaust the warm air and intake cool air.

Now, cool the air to just near 0 deg C and you can safely cool the food without causing any of it to freeze.

The trick is to cool off the food quickly so that bacteria don't have time to grow.

Not sure if you want to freeze the food, but, if you do then I think the same idea of removing any warmed air still stands as a good approach but you would replace the air with sub-zero air.

Answer 3

Good Question:
You could try rewiring the Microwave, switching the lead and the ground... :)

On a more serious note, I'd say because as yet there hasn't been much of a domestic need for it. Normally, freezing or refrigerating something works well enough. Perhaps you've started a new industry?

Answer 4

There already is a means to do it commercially thru the use of fast freezers......Rather than rewrite the info, I copied the following info from a website:

When freezing, it is important to freeze fast. Fast freezing causes the
formation of small ice crystals. Slow freezing causes the formation of large ice
crystals, which can damage proteins, resulting in a loss of elasticity, resorption, and water-holding capacity. Freezing at -22°C to -30°C causes 99.9% of the water contained in meat to be frozen. Microbial and enzymatic activity virtually ceases at these temperatures. One of the most common methods used to achieve a fast freeze is:

Cryogenics: This process is used primarily for ground and cooked products such as beef patties, fresh sausage, chili, soups, and stews. Liquid nitrogen or liquid carbon dioxide can attain extremely cold temperatures of -196°C and -78.5°C, respectively. Typically, patties or trays are passed through a conveyorized tunnel for a set time period to achieve freezing.

Answer 5

It's because the things you want cold are normally stored in aluminum cans and everyone knows that reverse microwaving aluminum cans is bad news.

Answer 6

The process whereby microwaves cause water molecules in food to vibrate and heat up is not reversible.

Answer 7

I guess a freezer is the closest we have but it is still not the same, that's a really good point.

Answer 8

you mean like the freezer

Answer 9

There is... it's called liquid nitrogen.

Answer 10

dude someone should invent that!