Before the fridge: how people kept food for months
Refrigerators in homes are barely a hundred years old. For all the centuries before, keeping food from spoiling was survival, and the tricks people used gave us some of the world's favorite foods.
Salt
Salt pulls water out of food, and the germs that spoil food need water. Salt cod, cured ham, prosciutto and corned beef all started as ways to make meat and fish last through winter or a long voyage.
Smoke
Smoke dries the surface of meat and fish and coats it with compounds that slow spoilage. Smoked salmon, bacon and barbecue traditions all grew from it.
Sun and air
Drying is probably the oldest method of all: raisins, dried figs, dried chilies, beans and grains. Jerky gets its name from the Quechua word ch'arki, dried meat from the Andes.
Fermentation
Here good microbes do the work: they turn sugars into acids that keep bad microbes out. That's how we got sauerkraut, kimchi, yogurt, cheese, miso, soy sauce and sourdough bread.
Pickling
Soaking food in vinegar or salty brine makes it too acidic or salty for spoilage germs. Cucumber pickles, pickled peppers, chutneys and escabeche all come from it.
Sugar and fat
A lot of sugar does what salt does, which is why jams and fruit preserves keep. Fat seals food from the air: French confit is meat cooked and stored in its own fat.
Cold, the old way
Before electric fridges, people used root cellars, springhouses and ice cut from frozen lakes in winter and packed in sawdust, sold door to door from ice wagons.
Safety first: home canning and curing have real risks if done wrong. Follow tested recipes from a source like the USDA or your local extension office.