Flash freezing (or blast freezing) refers to the process in various industries whereby objects are quickly frozen by subjecting them to cryogenic temperatures.
For example, flash freezing is used in the food industry to quickly freeze perishable food items (see frozen food). In this case, food items are subjected to temperatures well below water's melting/freezing point (32°F or 0°C), causing the water inside the foods to freeze in a very short period without forming large crystals, thus avoiding damage to cell membranes.
Flash freezing techniques are also used to freeze biological samples fast enough that large ice crystals cannot form and damage the sample. This rapid freezing is done by submerging the sample in liquid nitrogen or a mixture of dry ice and ethanol.
A supercooled liquid will stay in a liquid state below the normal freezing point when it has little opportunity for nucleation; that is, if it is pure enough and has a smooth enough container. Once agitated it will rapidly become a solid.
American inventor Clarence Birdseye developed the quick-freezing process of food preservation in the early 20th century.
This process was further developed by American inventor Daniel Tippmann by producing a vacuum and drawing the cold air through pallets of food. His process has been sold and installed under the trade name "QuickFreeze" and enables blast freezing of pallets in 35% less time than traditional flash freezing. This results in less potential food damage and improves Time to market.
Famous quotes containing the words flash and/or freezing:
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Shep: You yellow? Who thinks you’re yellow? Did you hear what he said? A guy who’s got the nerve to marry? That’s more than Flash Gordon ever did.”
—Billy Wilder (b. 1906)
“This is the Hour of Lead—
Remembered, if outlived,
As Freezing persons, recollect the Snow—
First—Chill—then Stupor—then the letting go—”
—Emily Dickinson (1830–1886)