It has been termed "Shetland's national dish"[1][2] The name reestit mutton comes from the Scots language word reest, meaning to cure by drying or smoking.

The correct ratio of coarse salt to water for the brine is achieved when a potato or egg will float in the solution.

[5] Some recipes also call for the addition of a small amount of sugar or saltpetre to the solution.

[5] Reestit mutton has a salty flavour,[7] which is also influenced by the peat smoke to which it is exposed when drying.

The soup is made with tatties (potatoes), and is commonly served with bannocks - small savoury scone-like baked items.