The process of how to make everyday bread was kept among women as tacit knowledge. A minority group in northern Sweden in the valley of Torneå, known as the Tornedalians, baked a soft bread called rieska (unleavened bread). Quite unlike other types of bread in the surrounding northern region, rieska is a type of bread that does not keep, which is why it is baked daily or weekly. The Sàmi people have also baked soft bread on stones on a more daily basis. The large Finnish minority group in Sweden has eaten a stiffer rye bread baked with sour dough. Bread was historically served in one of two ways, either broken into pieces in a soup or dipped in a hot drink, or served in the form of butter spread on a slice of bread and served as an open sandwich. In regions where they lacked cereals or bread, dried fish has functioned as bread. In order to make it edible, the fish was first beaten with a stone until it became soft. The fish was spread with butter and eaten like a sandwich. Potato came to replace bread as a staple food during the 19th century and bread retained its position as the main component of breakfast, but it became a side-dish to hot luncheons and dinners when potato took over the former central role of bread. Figure to the right shows the bread regions that existed around 1880, according to Åke Campbell (1950), before industrialisation led to all types of bread becoming available nationwide. Throughout history, the cities have always had a wider variety of bread types, as well as more expensive and higher status bread products in the form of cakes baked with sugar, butter and oriental spices. The boundaries should not be interpreted as being definitive, as cultural ideals always tend to vary along a boundary. During the switch to a modern urban and industrialised society, bread types changed when large industrial bakeries introduced new soft bread, which from the early 1920s was often sweetened (sötlimpa, sweet thick bread). From then on, bread was bought from stores and bakeries, rather than baked at home, as had previously been the case. Regional variations decreased due to the transportation and marketing of bread as a national product. The consumption of bread products of various kinds has increased since the 1990s and wholegrain bread and wheat bread are the most popular. All older bread types still exist alongside the new ones, indicating the much greater variety open to individuals today than has been the case in the past.