Medieval Food Preservation
from http://historymedren.about.com/

For centuries before the medieval period, and for centuries afterward, human beings in all parts of the world used a variety of methods to preserve foods for later consumption. Europeans in the Middle Ages were no exception. A society that was largely agrarian would be keenly aware of the need to store up provisions against the ominous threats of famine, drought, and warfare.

The possibility of disaster wasn't the only motive for preserving food. Dried, smoked, pickled, honeyed and salted foods had their own particular flavors, and many recipes survive detailing how to prepare foods that have been stored with these methods. Preserved foods were also much easier for the sailor, soldier, merchant, or pilgrim to transport. For fruits and vegetables to be enjoyed out of season, they had to be preserved; and in some regions, a particular foodstuff could only be enjoyed in its preserved form, because it didn't grow (or wasn't raised) nearby.

Food preservation methods were basically the same as had been used since antiquity, and did not change much until the invention of canning in the early 19th century. Foods which could not be preserved were only eaten when they were in season. Virtually any kind of food could be preserved. How it was done depended on what type of food it was and whether a particular effect was desired.

Drying was the most common and simplest method for preserving foodstuffs, but subjecting food to a number of chemical processes such as smoking, salting, brining, conserving or fermenting also made it keep longer. Most of these methods had the advantage of shorter preparation times and of introducing new flavors. Another method was to create a seal around the food by cooking it in sugar or honey or fat, in which it was then stored.

Here are some of the methods of food preservation used in medieval Europe.

Drying

The most common and simplest method was to expose foodstuffs to heat or wind to remove moisture, thereby prolonging the durability if not the flavor of almost any type of food from cereals to meats; the drying of food worked by drastically reducing the activity of various water-dependent microorganisms that cause decay. In warm climates this was mostly achieved by leaving food out in the sun, and in the cooler northern climates by exposure to strong winds (especially common for the preparation of stockfish), or in warm ovens, cellars, attics, and at times even in living quarters.

Salting

Salting was the most common way to preserve virtually any type of meat or fish, as it drew out the moisture and killed the bacteria. There were two methods of food preservation using salt as a preservative. Dry-salting where the meat or fish was buried in salt and brine-curing where meat was soaked in salt water. Vegetables might be preserved with dry salt, as well, though pickling was more common. Salt was also used in conjunction with other methods of preservation, such as drying and smoking.

Whatever method of salt preservation was used, the first thing a cook did when he got ready to prepare the salted food for consumption was soak it in fresh water to remove as much of the salt as possible. Some cooks were more conscientious than others when it came to this step, which could take several trips to the well for fresh water. And it was next to impossible to remove all the salt, no matter how much soaking was done. Many recipes took this saltiness into account, and some were designed specifically to counteract or complement the salt flavor.

Smoking

Smoking or salting meat of livestock butchered in the fall was a common household strategy to avoid having to feed more animals than necessary during the lean winter months.

Pickling

Immersing fresh vegetables and other foods in a liquid solution of salt brine was a fairly common practice in medieval Europe. In fact, although the term "pickle" didn't come into use in English until the late Middle Ages, the practice of pickling goes back to ancient times. Not only would this method preserve fresh food for months so that it could be eaten out of season, but it could infuse it with strong, piquant flavors.

The simplest pickling was done with water, salt and an herb or two, but a variety of spices and herbs as well as the use of vinegar, verjuice or (after the 12th century) lemon led to a range of pickling flavors. Pickling might require boiling the foods in the salt mixture, but it could also be done by simply leaving the food items in an open pot, tub or vat of salt brine with the desired flavorings for hours and sometimes days. Once the food had been thoroughly infused by the pickling solution, it was placed in a jar, crock, or other airtight container, sometimes with a fresh brine but often in the juice in which it had marinated.

Confits (as in duck confit)

Although the term confit has come to refer to virtually any food that has been immersed in a substance for preservation (and, today, can sometimes refer to a type of fruit preserve), in the Middle Ages confits were potted meat. To make a confit, the meat was salted and cooked for a very long time in its own fat, then allowed to cool in its own fat. It was then sealed up -- in its own fat, of course -- and stored in a cool place, where it could last for months.

Confits should not be confused with comfits, which were sugar-coated nuts and seeds eaten at the end of a banquet to freshen the breath and aid the digestion.

Sweet Preserves

Fruits were often dried, but a far more tasty method of preserving them past their season was to seal them up in honey. Occasionally, they might be boiled in a sugar mixture, but sugar was an expensive import, so only the cooks of the wealthiest families were likely to use it. Honey had been used as a preservative for thousands of years, and it wasn't limited to preserving fruit; meats were also stored in honey on occasion.

Fermentation

Most methods of preserving food involved stopping or slowing down the process of decay. Fermentation accelerated it.

The most common product of fermentation was alcohol thus killing any bacteria. Wine and mead could keep for months, but beer had to be drunk fairly quickly.

Freezing and Cooling

The weather of the greater part of Europe throughout much of the Middle Ages was rather temperate; in fact, there is often some discussion of the "medieval warm period" overlapping the end of the Early Middle Ages and the beginning of High Medieval Europe (the exact dates depend on who you consult). So freezing was not an obvious method of preserving foods.

However, most areas of Europe did see snowy winters, and freezing was at times a viable option, especially in northern regions. In castles and large homes with cellars, an underground room could be used to keep foods packed in winter ice through the cooler spring months and into the summer. In the long, frigid Scandinavian winters, an underground room wasn't necessary.

Supplying an ice-room with ice was a labor-intensive and sometimes travel-intensive business, so it was not particularly common; but it wasn't completely unknown, either. More common was the use of underground rooms to keep foods cool, the all-important last step of most of the above preservation methods.