Food Preservation 101 

happy food preservers

Happy food preservers show off their canned and frozen take-home products after 2012 on-farm workshop.

Julie and I have always enjoyed putting food by. One year she and the kids got me an Excalibur dehydrator for Father’s Day and I couldn’t have been happier. It sits by the kitchen table most of the year quietly drying the season’s products — peaches, pears, seedless grapes and cherry tomatoes for me, and various herbs and weeds for Julie. When the kids were here they would love to make fruit rollups by mixing ground fruit with a little honey, drying it on sheets until it was like leather, and then rolling them up.

We freeze all our meat and either freeze or can our vegetables and fruit for the year. That is, except for the potatoes, carrots, beets, parsnips, onions, rutabagas and various flower bulbs in our root cellar (along with a nice selection of home-made wines), and the shelves of lacto-fermented sauerkraut we make from cabbages. We don’t do much with salting or smoking, mostly because we don’t need to.

Food preservation, of course, is a practical means for anyone living in the northeast to convert food when it is relatively abundant (summer and fall) into something you can eat when it otherwise is scarce (winter and spring). Modern approaches enable us to maximize the preservation of nutrients and flavor, something that our ancestors often could not do as well.

The basic principle, to surround the food with an environment that will not support microbial life and thus prevent (or greatly retard) decay, is simple. Yet the many ways to do this – drying, freezing, salting, smoking, pickling, canning, jellying, cooling, burying in fat, fermenting, etc. are legion.

In this issue we explore a number of these techniques so that, if you don’t already do it, you can find out how satisfying (and thrifty) a pastime it can be. True, there is some work associated in cleaning and preparing the foods, as well as processing and then storing them.

But at our farm this was always an occasion for groups to get together, sit around the table, and joke or tell stories while slicing and paring, pitting and pressing, boiling and blanching. I think there are few better way to raise children to be helpful, productive, and conscious of the world than to have them help preserve food with the family. I hope you enjoy it as much as we do!




Food Preservation through the Ages

drying fish

Flattened fish drying in the sun in Madagascar. Fish are preserved through such traditional methods as drying, smoking and salting.

Throughout history people have learned to preserve food. Those living in temperate and brittle areas had to pass through months when growing was either impossible or chancy, so they preserved food as a matter of survival. Others did it to make food suitable for long distance trade, to supply soldiers, sailors, merchants or pilgrims who were traveling, or to savor a certain delicacy out of season. Sometimes the preservation method itself added particular desirable flavors. In some regions a particular foodstuff could only be enjoyed in its preserved form because it didn’t grow nearby.

Virtually any kind of food can be preserved. The principle of all such food preservation is to treat food so as to safely stop, or slow down, its spoilage. Even though it wasn’t until the middle of the 19th century and the work of Louis Pasteur that microbes were established as the cause of decay, practical observers long before then had discovered many ways to prolong the life of food. Here are some of the methods of food preservation used in pre-modern times.

Drying

It wasn’t hard to observe that food that is wet and left in the open quickly started to smell and attract bugs. So one of the oldest methods of preserving foods known to man is that of drying it. Most meats and fruit can be preserved through the drying process, and it is also the normal means of preservation for cereal grains such as maize, wheat, oats, barley and rye.

Grains like rye and wheat were dried in the sun or air before being stored in a dry (and rodent-proof) place. Fruits were sun-dried in warmer climes and oven-dried in cooler regions. In Scandinavia, where temperatures were known to plunge below freezing in the winter, cod (known as “stockfish”) were left out to dry in the cold air, usually after they were gutted and their heads were removed.

Meat could also be preserved through drying, usually after cutting it into thin strips and lightly salting it. In warmer regions, it was a simple matter to dry meat under the hot summer sun, but in cooler climates air drying could be done at most times of the year, either outdoors or in shelters that kept away the elements and flies.

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. Vegetables might be preserved with salt, as well, though pickling was more common. 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.

Dry-salting meat involved pressing dry salt into pieces of meat, then layering the pieces in a container (like a keg) with dry salt completely surrounding each piece. If meat was preserved this way in cold weather, which slowed down the decomposition while the salt had time to take effect, it could last for years. Vegetables were also preserved by layering them in salt and placing them in a sealable container such as an earthenware crock.

Thick saline baths were prepared in tubs each year to preserve fresh meats for the coming winter. While not as effective a long-term method of preservation as packing in dry salt, it served very well to keep food edible through a season or two. Salt brines were also part of the pickling process.

Whatever method of salt preservation was used, the first thing a cook did when getting 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. Spices were added to cooking recipes, and food was also served with a variety of sauces that also disguised the salt taste.

Pickling

Pickling was a standard method of preserving foods. 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 (a highly acidic juice made by pressing unripe grapes, crab-apples or other sour fruit) or 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.

Smoking

Smoking was another fairly common way to preserve meat, especially fish and pork. Meat would be cut into relatively thin, lean strips, immersed briefly in a salt solution, and hung over a fire to absorb the smoke flavoring as it dried — slowly. Occasionally meat might be smoked without a salt solution, especially if the type of wood burned had distinctive flavoring of its own. However, salt was still very helpful because it discouraged flies, inhibited the growth of bacteria, and hastened the removal of moisture.

Freezing and Cooling

In temperate regions with snowy winters freezing was at times a viable option to preserve food. But 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. 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 preservation methods.

Confits

A confit refers to virtually any food that has been immersed in a substance for preservation. They were often potted meat, made from fowl or pork (fatty fowl like goose were particularly suitable) that is salted, cooked in its own fat, and then sealed up in its fat in a cool place. Foods may also be preserved by cooking in a material such as gelatine, which solidifies to form a gel. Some foods naturally form a protein gel when cooked, such as eels. Confits should not be confused with comfits, which were sugar-coated nuts and seeds eaten at the end of a medieval banquet to freshen the breath and aid the digestion.

Fermentation

Most methods of preserving food involve stopping or slowing down the process of decay, but fermentation accelerates it! The most common product of fermentation was alcohol — wine was fermented from grapes, mead from honey, beer from grain. Wine and mead could keep for months, but beer had to be drunk fairly quickly. Cider was fermented from apples, and the Anglo-Saxons made a drink called “perry” from fermented pears. Cheese is also a product of fermentation. Cow’s milk could be used, as well as milk from sheep and goats.

Sweetness

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.

Canning

The history of canning is traced to France in 1795. The French government was involved with various foreign wars and the troops had to be fed. To solve the problem the French government offered a prize of 12,000 francs to anyone who could invent a method of preserving food for long periods of time. Finally, in 1809, a Parisian confectioner named Nicolas Appert produced a satisfactory method and collected the prize from Napoleon himself. Appert used wide-mouthed glass jars into which he put the food, and heated them to drive out the air, which he thought was the cause of food deterioration. Finally, he closed the jars with tight-fitting corks to keep the contents fresh. Soon, he was supplying bottled meats, milk, fruit and vegetables to the French Navy.

Over the years various people improved the process, using metal canisters and factory methods of production. When the American Civil War began only about 5 million cans of all foods combined were manufactured yearly. But because the American armies were so large and consequently unable to live adequately off the land, canned foods became almost essential. By the end of the Civil War that production had increased by about 600%.