Sturbridge, Mass. — Mrs. Gardner knew how to make soup. Cook up some butter, onions, flour, water, and ''a good piece of the upper Crust of the stalest Bread you have.'' Add salt, and ''Let it then stew or boil gently for ten Minutes, observing to stir it often.'' Beat two egg yolks in vinegar, stir them in ''Gently & by Degrees,'' and serve.
Result: onion soup, circa 1763.
Mrs. Gardner was an exception: she wrote out her ''receipts,'' or recipes. Most 18th-century cooking was taught by example - passed from mother to daughter , and never written down.
That fact poses a special problem for 20th-century history-lovers. Cooking was a central, time-consuming activity for early New England women, as evidenced in the large central fireplaces and blackened utensils of the period.
But how can later generations learn to appreciate the strenuous, persistent, and frequently smoky work of the 18th-century homemaker?
The museum staff at Old Sturbridge Village - a 200-acre re-creation of a rural New England village in the 1830s - has hit upon a solution. Each Saturday , from December through March, they offer ''Dinner in a Country Village.'' The ''guests,'' limited to 15 each evening, pay $25.50 apiece. The dinner itself is splendid: Mrs. Gardner's onion soup, mulled cider, an 1805 chicken pie, roast beef, and wafers filled with whipped cream.
But there's a catch. The actual cooking, done on the open hearth of a house built in 1748, uses only the tools and techniques of yesteryear. And it's done by the guests themselves.
Divided into small groups, under the direction of three costumed members of the museum staff, the guests slice the onions, hang the blackened iron kettle from the trammel over the fire, and boil up the water.
Others skewer the roast beef on the spit in the reflector oven, peel potatoes and carrots into a ''piggin'' (a small, wooden tub built barrel-fashion), roll out the rough rye-flour crust for the chicken pie, and whip cream with a whisk made of birch twigs.
It's all done by candlelight - and, unless the weather is just right and the chimney draws perfectly - in a haze of wood smoke.
But neither smoke nor onions have stopped the flow of teary-eyed participants. Village administrators, who began the program last winter, have had to add five extra sessions this season. Even so, the program is now fully subscribed - with a waiting list of 80 people.
Sturbridge Village spokeswoman Lilita Bergs attributes the success to ''a winning combination of hands-on experience. . . .'' Robert Olson, assistant director for interpretation, agrees. ''Visitors want to participate,'' he says, adding that Sturbridge Village began its ''Crafts at Close Range'' program 20 years ago as a way of providing hands-on experience in early New England crafts.
A few years ago, he says, interest in hands-on programs slumped. But in the last three years it has grown rapidly, as visitors increasingly want more than the passive relationships with objects in what he calls a ''glass-case museum.''
The hands-on trend is not limited to Sturbridge. The Henry Ford Museum in Greenfield Village, Mich., now has a new activities center where visitors can play 1980s games and experiment with radio sound effects from the 1920s. Eastfield Village, outside of Albany, N.Y., holds four- and five-day sessions in such things as tinsmithing, graining and marbleizing, and timber framing. Many other museums are also opening up ''after hours'' for special hands-on programs.
Sturbridge administrators, buoyed by the success of the dinners, are laying plans for a summer dinner picnic in 1984 - featuring light foods, outdoor cooking, and old games.
Meanwhile, for those wanting to sample Mrs. Gardner's cooking, the museum will soon publish a cookbook of more than 100 ''receipts'' - complete with tips for hearth cookery and what museum officials describe as ''tested, modern-day directions.''