As spring comes to Norwegia, dozens of fish are hung to dry on the huge wooden racks named hjell. The racks are set all along the foreshore in the north of Norway, for cold local winds and chilly temperatures are the most suitable for drying unsalted cod. The ideal temperature must be just above freezing, since fish fibers burst in the frost and it becomes inedible, while warm temperatures may result in bacteria. Being the world's oldest and cheapest method of food preservation, it is also quite effective. Stockfish may be stored for several years.