SOME people just eat. Others analyze what they eat in order to appreciate or reproduce it. Then there are people like George Lang, who view whatever goes into our mouths as data for history. He gathers it into books, essays and commentary on life as it was, is and will be lived.

Lang was in Washington recently to lecture to Les Dames d'Escoffier on what makes quality. So we asked him what today is making history. "The only culinary history being written today is in the U.S.," he responded, adding that what is going on in the rest of the world is negative history; culinary ground is being lost in homogenization. "We are at the stage the French were when they split from Italy and developed national consciousness," he boasted of America. Lest we rest on our laurels, though, Lang expressed disapproval of "American nouvelle" or "American-Continental" cooking that uses alien methods but calls itself indigenous, and he worried that simple-minded Tex-Mex or one-dimensional barbecued foods might be touted as full-blown American cuisine. As he concluded, "We are creating exciting--but limited--history."

The neatest trick we've learned this season is for keeping cottage cheese fresh. If you store the carton upside down, we were told, the cottage cheese is exposed to less air (because air is forced out and a partial vacuum is formed, was the reasoning), thus spoils less quickly. We tried it and it worked; the right-side-up carton deteriorated much faster than the upside down, though both had been partially consumed. The only problem is keeping people from automatically righting the carton when they come across it in your refrigerator.

This is the season to hone your cooking skills on somebody else's range, for several stores have scheduled free cooking demonstrations. To start, Someplace Special, Giant Gourmet in McLean, has booked top French chefs of Washington to show their tricks. Next Tuesday, Jan. 25, Pierre Chambrin of Maison Blanche will appear from 4 to 5:30 p.m.; Thursday, Jan. 27, it will be Jean-Louis Palladin of Jean-Louis from 1 to 4 p.m.; and Friday, Jan. 28, Gabriel Aubouin from La Brasserie will demonstrate from 1 to 4 p.m. Shoppers can sample the chefs' wares and other French foods during the demonstrations, and the Giant kitchens will be preparing these chefs' recipes to sell in the "Gourmet-To-Go" section during the two-week French food festival.

The cooking will be Italian at Williams-Sonoma, when Jo Bettoja, co-author of "Italian Cooking in the Grand Tradition," demonstrates on Tuesday, Jan. 25, at 1 p.m. in the Mazza Gallerie store.

And it will be down-home in the back-yard garden at Kitchen Bazaar the same day and same time, as Lois Burpee shows and tells what is in her new "Burpee Gardener's Companion and Cookbook." That's at the 4455 Connecticut Ave. store, Jan. 25, 1 to 2:30 p.m.

Nearly 30 years ago one of Washington's utility companies presented the kitchen of the future; it was a computerized conveyor-belt sort of operation that, with the press of a button, heated the oven, removed the foods from the freezer and cooked them at the proper time for all the dinner to be ready simultaneously. Sears is still predicting something similar, though it adds to the fantasy a computer that not only cooks dinner but protects your home from burglars and does your shopping and financial planning.

It's not here yet.

But along the way Sears has come up with two interesting new twists on appliances and one fantasy gone awry. The interesting ones are an induction cooktop, which heats a smooth ceramic glass surface only when a pot or pan with some iron content is on it. We can't guess how well it cooks, but it does away with the problem of forgetting to turn off the stove. Then there is the refrigerator with doors that become transparent when a button is pushed, so you can survey the contents without opening the door.

The wacky one is Sears' new microwave oven. Who hasn't looked at a microwave door and imagined turning on the soaps or watching the news on that TV-screen look-alike? So Sears has added a television (and a stereo cassette player) to its microwave oven, but it is a teensy little 5-inch screen above the control panel, not what fantasy dictates for that big microwave door. The real question is, who wants to sit in front of a microwave oven when it is running?

While Americans unwrap another slice of "processed cheese food," the French are so disgusted with the state of camembert, says a Paris news report, that French homes are consuming only five whole camemberts a month these days. The problem, quoted from a French economic advisory board, is that there is not enough competition among camembert producers, so prices have been increasing while quality has slumped. We wonder when we should expect to see it, too, wrapped in sandwich-size plastic squares.