It is traditionally baked in a pot or steamed in special wooden casks by burying it in the ground near a geyser, in which case it is known as hverabrauð [ˈkʰvɛːraˌprœyːθ] or "hot-spring-bread".

Stale rúgbrauð is often soaked, then made into brauðsúpa ([ˈprœyːðˌsuːpa], "bread soup") – that is, simmered with raisins and flavorings (usually lemon) and served hot with whipped cream as a dessert.

Excessive consumption of this bread is said to cause flatulence, earning it its nickname þrumari, which roughly translates as "thunderbread" or "thunderer".

In September 2022, American seismologist Julian Lozos attempted to bake rúgbrauð in his car during a heatwave in the San Fernando Valley.

Whilst unsuccessful, Lozos' attempt was covered in the Icelandic press and earned him an interview with Ryan Seacrest.