Why food preservation is important
While the urban population during the Viking age may have had access to frequent markets or food stalls, the majority of the (rural) Vikings population had to rely on food preservation to survive the winter. Most Viking farmers had comparatively small holdings, and produced food mainly for the subsistence of their own families, rather than generating cash crops what would allow them to purchase food from external sources.
In a subsistence farming economy, each farming household had to rely on the produce of their farm for the majority of their living. Given the short growing season in the North, it was even more important to preserve the farm’s produce over the winter.
Almost all of the techniques for food preservation that we rely upon today were unknown in the Viking Age. There were no refrigerators, no canned food, and no freeze drying (at least as we know it today). The Vikings had to rely on traditional methods of food preservation.
Some vegetable foods can be preserved in their “raw” form over the winter, particularly in a cool climate. Onions, root vegetables, and to some extent cabbages can be preserved by burying them in sand or loose soil, or storing them in hay in a cool place like a root cellar. Since Viking cabbages were not headed cabbages like we have today, they probably didn’t hold up to such treatment as well as modern head cabbage.
How was food preserved
Many different foods can be preserved by drying, including grain, meat and fish, vegetables and fruit. Drying is well suited to the cold and often windy conditions prevalent in Northern Europe, and requires little in the way of resources. Dried food can be kept for long periods of time as long as it is kept away from moisture. Foods with a high fat content do not dry well without salt or other anti-bacterial agent.
Many different foods can be pickled, either in vinegar, salt, or other acids such as soured whey. In areas where salt was affordable, meat, vegetables and fish can be pickled in salt. In areas where salt was more expensive or unavailable, the same foods could be preserved in vinegar or sour whey. Soft vegetables, and fattier meats such as pork lend themselves well to pickling.
Some foods can be preserved in salt without liquids, such as some cheeses, smoked fish, or fatty meats like pork. However, the farther north you go in the Viking world, the less likely it is that salt was readily available or affordable. In Iceland salt was essentially absent, so pickling in acid or drying were much more practical. In the South, such as parts of Denmark or the Danelaw in England, salt would have been more available and affordable, making things like bacon, ham, or smoked fish more popular.
There are a whole host of bacteria that can be employed to preserve food for human consumption. Lactobacilli can pickle meat and vegetables by producing acid in liquids. Cheese, soured milk, and other dairy ferments are all produced by bacteria as well. Fermentation also produces alcohol, vinegar, and a wealth of other healthy and long-keeping foods.
Smoking is particularly important in keeping food that has a high fat content and will not be kept in liquid, such as ham, bacon, smoked fish or smoked cheeses. Smoking by itself is not sufficient, and smoked foods usually need to be salted as well. Smoke was also used to preserve some foods on a day to day basis. Dried breads were hung from a pole or string over the hearth, where the heat and smoke kept them dry and free from insects.
What was preserved
Grains such as barley, rye and oats can be preserved for a limited time just by drying. But grain in bins can only last so long. There are several ways of making the calories from grain last longer.
Bread or crackers baked hard will keep longer than grain by itself. Hard tack or crisp bread dried completely and stored in either waterproof containers or over the fire will keep nearly indefinitely. They are easy to eat, easy to store, and easy to transport. Thin dried bread (like modern rye crisps) can be eaten plain or with fish, cheese, or whatever you might have. Hard tack is best soaked or cooked in liquid before eating. You can break up hard tack for “porridge” or use it to thicken soups.
Calories from grain can also be preserved in the form of beer. By converting some of the grain’s starch to alcohol, bacteria or other contaminants can’t grow, and the calories are preserved. However, it is unclear how long the kind of beer made by the Vikings would really have kept. Given the brewing techniques available, beer may have been comparatively perishable.
The Vikings had access to a wide variety of fruits, and many of those are comparatively easy to store. Some fruit can be dried, some pickled, and a few might keep in a cool place well into the Fall at least.
Several easily dried stone fruits, including cherries and plums of various kinds were known to the Vikings. Apples can be dried as well, and some berries can be dried in a dry enough climate.
Apples in particular are traditionally pickled all over Europe today, and lend themselves well to it.
It is traditional in Finland to store lingonberries in water, which then freezes during cold weather. There’s no evidence (that I’ve seen) to suggest this was common in the Viking Age, but it’s not something that would be likely to show up in the archeological record.
Some vegetables will keep for a long time in cold storage if properly packed and cared for, such as turnips, carrots, parsnips, onions, and garlic. See above note on cabbages.
The most likely way to preserve vegetables is by fermenting them. Lactic acid pickles are easy to make, delicious and nutritious to eat, and contribute to a healthy digestive system (as modern science is rediscovering). Sauerkraut and “kosher” or “sour” dill pickles are good modern examples, but other vegetables like turnips, carrots, celery and others can all be pickled this way. Once you have a good bacterial culture, such pickles can be made with little to no salt, as it is primarily the lactic acid produced by the friendly bacteria that keep out the unfriendly ones.
The most common way to preserve meats is with salt. Salts of various types (sodium/potassium/etc.) keep unfriendly bacteria from getting into meat and allow it to be stored for long periods. Smoking will help fattier meats keep longer than salt by itself, as will immersing them in liquid (brine) since the liquid helps keep oxygen away from the meat.
Acid solutions such as vinegar or soured whey can also be used to preserve meats. Sausages in particular have traditionally been pickled in brine, in vinegar, in sourced whey, or by themselves. In Iceland they still use sour whey to preserve sausages made at slaughtering time, and such was most likely the case in the Viking Age as well. Some traditional (i.e. early modern) sausages are made with rye flour added to them. When rye flour is left in water, it sours naturally, so the rye-laden sausages were placed in jars of water that soured and thus preserved the sausages. Note: any such meat preserved in acid without salt is cooked first before being submerged.
Many oilier fish can be readily pickled. Herring, sardines, anchovies and possibly mackerel-esque fishes can be pickled in salt or in a lactic acid solution. The pickled herring that adorn the modern Scandinavian table are certainly different, since they tend to contain a fair amount of sugar and spices that were unavailable in the Viking period, but the overall effect would have been the same. Chopped up bits or herring suspended in a sour solution, possibly with the addition of some salt if available.
One of the great mainstays and staple foods of the Viking world was dried cod. Because cod contain almost no fat, they can be dried hard in the cold and windy Scandinavian climate, and will keep pretty much as long as they can be kept dry. The Viking warriors who travelled overseas took dried cod with them, and in a pinch were known to gnaw on the dried fillets all by themselves. In a more comfortable setting, the stockfish, or klipfisk, would have been soaked in liquid until they were soft(er) and made into soup or mixed into other dishes.
If salt is available, oilier fish can be smoked. Salmon, herring, haddock, and mackerel can be smoked and preserved for long periods, although not as long as cod.
Only a very few Scandinavians are lactose intolerant compared with rates in the rest of the world. It has long been speculated that this is because dairy products are easy to produce and the keep in their climate, which makes the ability to digest milk into adulthood a survival characteristic. Whether that is true or not, it is certainly true that milk and milk products have long played an integral role and source of nutrition in Scandinavia since well before the Viking Age. Dairy products are one of the few food products mentioned in the sagas, so there is some good documentary evidence for milk and milk products in the Viking period.
If raw (unpasteurized) milk is left out in mild temperatures, it will naturally grow lactobacilli that cause it to sour. Sour milk was commonly drunk as a beverage and probably used in cooking, baking, and in making cheese. In early modern Sweden, sour milk was mixed with small beer both as a beverage and as a cooking medium. If sour milk is heated, it will coagulate, and can then be drained to make a simple cheese to be eaten fresh, or preserved with salt or further bacterial action as cheese.
The simplest fresh or “farmer’s” cheese can be made from soured milk or fresh milk which is heated and coagulated by the addition of soured milk or other acids.
Milk can also be combined with rennet to create a whole variety of cheeses and cheese products. If salted and dried, “hard” cheeses can be kept for very long periods of time without spoiling.
Skyr is somewhere between a cultured milk and a cheese. It is cultured with lactobacilli much like yogurt of buttermilk, but it also is coagulated with rennet. Once the rennet causes it to set, the curds are drained, and the result is very similar to a drained yogurt. It is mildly sour and quite dense, and contains a great deal of protein. Skyr is traditionally made with skim milk, since the milk fat was used to make butter. Skyr was a mainstay of the Icelandic diet, and was eaten by itself, with fruit, or mixed into porridge or other dishes to stretch them and to add additional protein.
The milk fat from cow’s milk is easily converted into butter, which has a much longer shelf life than fresh milk. Also, since the Vikings tended to make butter from cultured or soured milk, the additional acid content would help preserve the butter.
Other cultured milk products
The documentary evidence speaks mainly of “sour” milk, but it is unclear if that means raw milk that sours naturally, or milk which was intentionally cultured. In modern Scandinavia, there are a number of cultured milk products that are “traditional” (meaning at least early modern) but there is no telling how far they go back. Piima, viili, and fil mjolk are all examples of modern Finnish or Swedish dairy cultures. They are fairly easy to obtain and to propagate, and may come close to simulated the naturally soured milk that we can no longer achieve with pasteurized milk today.
What evidence do we have?
Unfortunately, fermented foods are difficult to distinguish in the archeological record. Most food products decompose rapidly, and if anything is left it is the hard parts like seeds and bones, where it would be almost impossible to tell if they came from preserved foods or fresh. There is some evidence from the sagas about butter, cheese, skyr and sour milk, as well as dried cod. Several pieces of carbonized breads have been found in various Viking contexts, and good analysis has been done on their composition.
Luckily, a few artifacts have survived that are linked to food preservation
- The bottom board from a rectangular cheese press made of wood, similar to those used in Aland in the early modern period
- Several wooden butter churns
- Curd strainers, both wooden and hair
- Vegetable matter from potsherds consistent with fermentation
Hansson, Ann-Marie. On Plant Food in the Scandinavian Peninsula in Early Medieval Times. Theses and Papers in Archaeology B:5. Stockholm: University of Stockholm. 1997.
Isaksson, Sven. The culture of food in Early Medieval Middle Sweden. A pottery use perspective.Food and Rank in Early Medieval Time. Stockholm: University of Stockholm. 2000.
Jørgensen, G. et al. Analyses of Medieval Plant Remains, Textiles and Wood from Medieval Svendborg. The Archaeology of Svendborg 4, Odense: Odense University Press. 1986.
Early modern references
Bringéus, Nils-Arvid. “A Swedish beer milk shake.”Milk and Milk Products from Medieval to Modern Times. ed. Patricia Lysaght, pp. 140-150. Precedings of the Ninth International Conference on Ethnological Food Research. Edinburgh: Conongate Academic, 1994.
Gísladóttir, Hallgerður. “The use of whey in Icelandic households.” Milk and Milk Products from Medieval to Modern Times. ed. Patricia Lysaght, pp. 123-129. Precedings of the Ninth International Conference on Ethnological Food Research. Edinburgh: Conongate Academic, 1994.
Modern works on food preservation
Nourishing Traditions, by Sally Fallon
Wild Fermentation, by Sandor Katz
Truly Cultured, by Nancy Lee Bentley
Preserving Food without Freezing or Canning, by the Gardeners and Farmers of Centre Terre Vivante
Making sauerkraut and pickled vegetables at home, by Klaus Kaufmann
Charcuterie, by Michael Ruhlman and Brian Polcyn
http://www.culturesforhealth.com/ in Oregon City has several dairy as well as vegetable cultures, and fermentation and cheese making equipment.
http://gemcultures.com/ in Lakewood, WA has several dairy cultures.
In the past I’ve gotten piima and fil mjolk cultures from www.fermentedtreasures.com, but their server seems to have gone kaplooey.
http://www.kookoolanfarms.com in Yamhill has lots of cheese making supplies, as well as raw cow’s milk
http://www.cheesemaking.com is Ricki Caroll’s excellent cheese making supply company.