If you can't stand the heat ...

If necessity is the mother of invention, the kitchen is surely one of the great arenas of technological change. The pace was slow through the first two-thirds of the millennium, but the impetus behind 1,000 years of kitchen developments has remained the same: to move food from larder to table efficiently.

From the large, open fireplace of a medieval shopkeeper's house, to the grandiose layout of a 15th-century nobleman's kitchen, these rooms were indicators of wealth - and often a virtual slave quarters for the women and servants who worked in such torrid environments. Not until the stove appeared in the 17th century did the kitchen as we know it begin to take shape.

The first innovations dealt with regulating cooking temperature. In wealthier homes, servants used hooks, suspension chains, and pulleys to raise or lower cauldrons, controlling the amount of heat supplied. Such a system seems to have been the major improvement of the late Middle Ages.

As European explorers brought back foods and spices from far-off lands, wealthy citizens had greater access to exotic ingredients, but cooking techniques remained almost unchanged, with two exceptions:

In the mid-17th century, an anonymous cook discovered that cooked meats would keep longer sealed in a layer of fat thick enough to keep air out.

The second innovation occurred in 1679 when French-born physicist Denis Papin invented the pressure cooker. Called Papin's Digester, this airtight cooker produced a hot steam that cooked food more quickly while preserving nutrients.

During the 16th and 17th centuries, common people began to use the plate, usually made of wood or, for those who could afford it, metal.

"You had only one and you carried it with you," explains Andrew F. Smith, culinary history professor at New York's New School. Guests also brought their own knives, and later, their own forks.

Although the fork dates back to Roman times, for centuries it was used only in the kitchen to hold down large pieces of meat for carving. By the year 1000, Byzantine nobility had begun using small gilt forks for sweetmeats. From there, the fork traveled to Greece and by the 14th century was used by some Italians. But it was not until the 17th century that northern Europeans adopted the fork, and not uniformly.

Colonial Americans built kitchens remarkably similar to those of their medieval European ancestors. The housewife cooked in the fireplace with iron skillets and pots called kettles. She also had a few other iron tools such as gridirons for roasting meat, a waffle iron, a Dutch oven for baking rolls, and a wire frame for toasting bread. The open hearth demanded the woman's constant attention. She had to keep the fire going and prevent her small children from getting burned by flying cinders. In Southern plantations, the kitchen was often a separate building, which protected the owners from the oppressive heat the slaves endured.

But with the Industrial Revolution, the kitchen began to change.

One of the more important developments was canning. "The canning revolution made it possible to have large modern urban cities," Prof. Smith says.

In the 1700s, European housewives began preserving fruits in boiled-sugar syrups. In 1809, after 14 years of experimentation, French confectioner Nicholas Appert developed canning, by hermetically sealing fruits, vegetables, meats, and milk in glass bottles, and then processing the bottles in boiling water. Napoleon had offered a large prize to anyone who could develop a new method of preserving food so that he could more easily feed his troops.

Home canning didn't become popular in the United States until the early 1900s. By then, machine-made jars replaced hand-blown glass bottles.

For home cooks, the improvement of the stove was perhaps the most important advance of the past 1,000 years. The earliest stoves were designed for heating rather than cooking. In the late 1700s, American-born physicist Benjamin Thompson, later known as Count Rumford, invented the Rumford fireplace, one of the first cast-iron cookstoves.

"Rumford is an exemplar of the application of science to food," says Smith. A refinement of the open hearth with cubbyholes, Rumford's metal cookstove - which could be put anywhere, regardless of where the chimney was located - reduced coal smoke, burned hotter and faster, and yet the heat could also be adjusted.

Swedish engineer Nils Gustav Dalen designed a better stove while recovering from an accident. While convalescing at home, he noticed how much time his wife spent caring for their wood-burning stove. This practical man decided to invent a more efficient and cost-effective stove.

In 1922, Dalen's Amalgamated Gas Accumulator Co. patented his design and put the first AGA stoves into production. These stoves produced a radiant heat that kept the kitchen warm. The AGA remains popular today, especially in drafty English country houses.

In the 1880s, the closed range was hooked up to gas and in the 1890s, to electricity. Food historian Rachel Laudan, author of the forthcoming book "Power Cuisine and History'' says, "No other change in kitchen technology compares to this - the closed gas or electric stove. It made the kitchen cleaner and pleasanter; you could begin cooking with the turn of a knob instead of needing to allow a couple of hours to get the fire going. It transformed cooking methods."

Ms. Laudan adds that the enclosed stove "led to the great North Euro-American invention, the cake-cookie-pie complex. Before this, baking was a specialist trade. Admittedly, home baking also relied on chemical raising agents, refined white flour, refined white sugar, all of which had become cheap and widely available in the previous half century."

Home refrigerators and freezers arrived in American homes somewhat later. In the US, the Shakers built some of the first ice houses, using sawdust and straw to keep large chunks of ice from melting too quickly. Individual families used a smaller version, the icebox, an insulated box kept cool as a large chunk of ice, delivered weekly, evaporated.

Ice-making machines began to be patented in the 1830s. Refrigeration was being developed about the same time. In 1867, a prototype refrigerated rail car was patented, and soon trains and ships had refrigeration compartments.

After World War I, many Americans began replacing their home iceboxes with refrigerators that had a small freezing compartment. "American housewives took to the mechanical refrigerator as fast as their finances would allow," writes Sylvia Lovegren in her book "Fashionable Food." Those early refrigerators were easier to clean and regulated temperature better than the old-fashioned icebox had. Women could store food more easily, even freezing small quantities, and therefore needed to shop less often.

"With the car and the supermarket, the refrigerator made weekly [rather than daily] shopping possible," Laudan says, adding that the home refrigerator "started America's enchantment with the chilled," from cold drinks to ice cream.

By the mid-1950s, more than 80 percent of American households had a refrigerator, compared to only 8 percent of English households, Ms. Lovegren notes.

Home cooks began buying commercially frozen foods in the 1930s, after Clarence Birdseye started selling his line of "frosted foods." (The word "frozen" was associated with food that had gone bad because of cold weather.)

Most of the gadgets modern cooks take for granted were invented in the past 150 years. In the second half of the 1800s, "Eggbeaters, cherry stoners, apple parers and corers, butter churns, meat choppers - all these and more were patented in large numbers," but few households owned them, Strasser writes.

Laudan sees the application of the small electric motor to kitchen appliances as an important development.

By the 1930s, housewives could buy electric devices ranging from chafing dishes, waffle irons, hot-plates, mixers, toasters, and even a free-standing portable oven. "Electric gadgets were the darlings of the 1930s, evidence of the modern age even in the midst of Depression," Lovegren writes.

By the 1970s, American cooks had even more gadgets at their disposal, such as the food processor, the microwave, and the slow cooker, best known by the brand name Crock-Pot.

Lora Brody is the author of "Lora Brody Plugged In: The Definitive Guide to the 20 Best Kitchen Appliances.'' Her pick for the most important modern kitchen appliance? "The easy answer would be the food processor, but my answer would be the slow cooker. Nothing has as many applications as the slow cooker."

The microwave was the largest and perhaps the most important of the kitchen gadgets that became popular in the 1970s. While some brush it off as a device to heat water and reheat frozen food, Smith notes that 64 percent of American homes now have a microwave oven.

Lovegren says, "I think in this century, the microwave is without a doubt the big evolutionary leap because it's made reheating take-out food and frozen entrees possible," which is leading to "the death of cooking in the modern world."

"I think it will take a while, but most people I see around me, except for immigrants or people with strong ethnic backgrounds, don't do any cooking," with the exception of entertaining, she says.

Preparing elaborate dishes for dinner parties is "like a fun hobby or an accomplishment like in Jane Austen [novels] when everyone comes over and the ladies show how prettily they can play the piano," Lovegren says.

Laudan is more circumspect about how the microwave will affect cooking. "We won't know its full impact for another few decades - inventions take that long to find their place - but it's clearly implicated in the move away from meals and toward snacking."

(c) Copyright 2000. The Christian Science Publishing Society