Drying is a method of food preservation that
works by removing water from the food, which prevents the growth
of microorganisms and decay. Drying food using the sun and wind
to prevent spoilage has been known since ancient times. Water is
usually removed by evaporation (air drying, sun drying, smoking
or wind drying) but, in the case of freeze-drying, food is first
frozen and then water is removed by sublimation.
Many different foods are prepared by drying,
including Parma ham, bresaola, beef jerky, and even fruits that
normally have a high water content, such as prunes, raisins,
figs, and dates.
Dried and salted reindeer meat is a
traditional Lappish food. First the meat is soused. It is kept
in saltwater for a couple of days to guarantee the conservation
of the meat. Then the meat is dried in the sun in spring when
the air temperature is below zero. The dried meat can be further
processed to make soup.
There are many different methods for drying,
each with their own advantages for particular applications;
- Bed dryers
- Fluidized bed dryers
- Shelf dryers