Because of the unavoidably conjectural nature of this project, the second pillar of our development is a close look at the food preparation technology available during the Viking Age, including processes and equipment for which we have evidence.
Boiling
Boiling was likely the most ubiquitous method of cooking in this cultural context. Of the methods we know existed at the time, it is the most fuel-efficient due to the direct transfer of heat from the fire to the water in the cauldron. This would have been a major factor in the Atlantic settlements where fuel was far more scarce than the Scandinavian core, which held vast reserves of timber. In addition, it retains the largest proportion of nutrition compared to other cooking methods (any fats, juices, or starches from the food remaining in the broth) and that presence of water and retention of meat juices and fats would be essential to cooking legumes, grains, or meat. (Serra 23)
In what we have of the Old Norse textual culture, Boiling was synonymous with cooking, and there were a variety of vocabulary words around the practice in use. Words such as hvergætir (cook, lit. “kettle-guarder”) soðhús (kitchen, lit. “boiling house”) and sjóða (to cook, lit. “to boil”) came to be used as the generic words for those meanings, but were originally words specifically tied to boiling. Throughout the Sagas, ketill (boiling pot) is the only vessel for cooking described, and while meat roasting is also described, rarely, even the meat served in Valhǫll is described as boiled. (Ashby 6, 25, 26)
The legal traditions of Iceland tell us more about the vessels, including that iron was the preferred material of a valuable cooking pot, and that a proper pot measures about twelve inches diagonally from bottom to top.(Ashby 11) In Ólafs saga Helga (ch. 189) the writer also uses the term steinkatli, referring to a kettle made of stone. (Adalbjarnarson II, 392) One assumes this is a soapstone kettle, which we know to have been common among representative archaeological finds in Scandinavia. Archaeological finds also show the use of ceramics as cookpots. (Serra 22)
Baking
While ovens were rare throughout Scandinavia during our time period, if we adopt a broad understanding of baking to mean prolonged cooking by dry heat either enclosed or directly on hearthstones or in embers, it becomes a central cooking method to examine. This is one of the most basic methods of cooking, and it persists around the world to this day. It is especially suited to root vegetables and loaves of bread, though with ingenuity (or a tolerance for ash) it will cook just about anything that does not require a large amount of liquid. Direct-heat baking such as this is also extremely fuel-efficient, and can take place around the same fire being used for boiling, making the combination doubly so.
Archaeological evidence suggests thin loaves of bread were cooked on an iron griddle or hot stone prior to the popularization of ovens toward the later part of this era. From all over Sweden, and especially the Birka burials, many distinctive types of bread were identified, including “thin, soft, foldable flatbreads made on a griddle pan – rather like a sort of Nordic tortilla, to be stuffed with food.” Likewise, thin, crisp flatbreads with a hole in the middle for storage on a wire were prepared on the same sort of griddle. There were also biscuit-like breads similar to modern griddle biscuits, and crisp twisted breads that could be compared to pretzels. (Price 118) The Icelandic textual evidence also indicates a specific type of fire, bakstreldr, used for making bread over it. This would require either a hot stone adjacent to the fire, or a griddle like those found in the archaeological record. (Ashby 25)
Although griddled flat breads appear to have been the most common household form, clay ovens did become popular in the later part of this era as mentioned above, such as the clay dome ovens found at Haithabu (Hedeby.) Several of the variety of breads identified around Sweden required an oven to bake effectively, such as rectangular loaves baked in a form, and oval-shaped buns. (Price 118) While not as fuel-efficient as boiling or direct-heat baking, oven baking is still highly efficient.
Roasting & Grilling
Though mentioned infrequently in the Sagas, the Icelandic textual record gives us the words steikja á teini (to roast on a spit) and brass (roaster, cook) in acknowledgement that it was used. (Ashby 25, 27) We likewise have archaeological evidence of meat spits, both large as one might use for an animal over the fire, and narrow as one might use to serve some kind of kebab at the table. (Price 119) Roasting is, by far, the most time-consuming and least fuel-efficient method of cooking, requiring offset radiant heat and constant attention. However, as the modern diner can attest, it produces delicious results. Even if a vessel were used to capture the drippings, some amount of fat and juices would also be lost. Like direct-heat baking, however, it would be possible to roast meat on a spit beside the fire while also using a cauldron over the fire to capture the heat. One can imagine a kettle suspended over the fire, parsnips and beetroots laying on the rocks beside it, and a small spit set up beside the fire to roast fowl.
Grilling is a cooking method for which there is scant evidence in this cultural context. A single iron grill has been found, and there is contention over its purpose. It is, however, entirely plausible that it was designed to be suspended over a fire for what we would modernly think of as grilling. (Serra 25) Although this method could be simultaneous with direct-heat baking, the grill perhaps even serving to hold the iron griddles for bread, it would not be compatible with boiling on the same fire. This makes it by far the most fuel-intensive method, and would also require relatively constant attention and care from the cook. There is also no question that fat and juices from meats prepared this way would be lost to the fire.