Knäckebröd is a fermented hard bread, the opposite of soft bread, and initially originated from Sweden. It has been in the Swedes diet since the Middle Ages. Originally it was called stove bread since it was baking directly on the stove. The stove bread is the precursor to today's knäckebröd or crispbread, but then it was thicker and coarser. Traditional knäckebröd is bake on only four ingredients – rye (usually whole grains), yeast or sourdough, salt, water. Today, the knäckebröd ranges at the various bakeries have developed so that other grains also could be included. Today you will also find knäckebröd containing wheat, barley, oats or corn. Now there are also lots of flavoured varieties as the taste of knäckebröd lovers develops all the time. Here you will find all kinds of knäckebröd, the traditional varieties as well as knäckebröd flavoured with seeds, herbs or spices.
The knäckebröd has the name after the fact that when you bake it, you use a tool with thorns that created lines to make it easier to break the knäckebröd into parts. The word knäckebröd itself is a composition of the Swedish phrase knäck or knäcka (crack) and bröd (bread).
Here's how ethnologist Åke Campbell wrote in his 1950 book "The Swedish Bread":
"For Swedish bread culture in large parts of old Sweden, hard- or chewy, fermented rye bread or rye mixed bread are particularly characteristic. The bread mentioned above (p. 177), under the name of stove bread or knäckebröd, are round and provided with holes for string or bread bar. They are patted and rolled out, considering they should be hanging up to dry without breaking or folding too much. Knäckebröd can be made about 30-40 cm in diameter and about 1/2 – 2 cm thick. The bread is cracked with a special tool, "krusknäck" are usually nailed or picked only on one side."
Due to the low liquid content of a baked crispbread, it has a perfect shelf life. It was a characteristic that was important in the past when knäckebröd use to be a storehouse bread, a bread that could be stored for a long time, which was an essential feature of the old peasant society. To this day, this is a much-appreciated feature. If you keep a crispbread dry, it will last almost forever. To have crispbread at home is always to have access to a piece of good and very healthy bread. A well-stored knäckebröd does not result in food waste. The bread tastes just as good all the time. Grind the crumbs into breadcrumbs or break them into small pieces and crumble over the yoghurt.