Joanna Preuss used to cook blindfolded

That was the only way she could experience firsthand some of the obstacles blind people encounter when confronting the mystifying world of a kitchen. Ms. Preuss learned to minimize the danger of burns by having her blind students sprinkle apple tarts with cinnamon sugar before the tarts went into the oven rather than midway through the baking process when they would have to cope with a hot oven. In addition, ``I discovered that when you make pastry dough in the food processor, it makes a discernible change in sound when the mixture reaches a certain stage,'' she says.

Thanks to efforts like this, the joy of cooking has become more accessible to blind, learning-disabled, and hearing-impaired people.

``These kinds of handicaps shouldn't be a barrier any more,'' says Preuss, a food historian, free-lance writer, and former fashion designer who is now director of the Cookingstudio, a cooking school located in Kings Super Market in Short Hills, N.J. ``Not being able to see or hear doesn't mean you don't love good food. It just means you may not have had a chance to advance your skills.''

The school with which she has set out to improve this situation is a huge, cheerful, family kitchen with curtained windows that look out onto the supermarket shopping area. Its counters are lined with food processors, cookbooks, copper pans, and pots of chives.

Recently, 13 children, aged 11 to 13, from the Lake Drive School for the Hearing Impaired in Mountain Lakes, N.J., attended one of Preuss's classes.

With the help of a sign interpreter, they spent 2 hours learning to make tomato sauce, meatballs, homemade pasta, and fruit salad. With great enthusiasm they cut onions, broke eggs, stirred the sauce and, best of all, to judge from their excited giggles, cranked dough through the pasta machine. `CAN my mother and I come again tomorrow?'' asked 10-year-old Johnny Castrese of Wyckoff, N.J.

``I liked making spaghetti and meatballs because it's my favorite food,'' signed Roni Lepore, 13, of Rockaway, N.J. ``I liked using the pasta machine because you don't have to cut, cut, cut.'' THIS kind of program would be good for all children, but it's especially good for the hearing-impaired because it's all so visual,'' says Renia Kaufman, the students' communications teacher. ``So often they go someplace and there's a communications barrier. Here they can get actively involved and understand everything.''

To teach the learning disabled, Preuss has learned to simplify, be direct, avoid subtleties, and stay with the here and now. ``I make cooking entertainment,'' she says. ``For instance, I had the students yell `onions' when the timer said they had saut'eed long enough.''

Joanna teaches her blind students, who use Braille timers and measuring cups and spoons provided by the New Jersey Commission for the Blind, to rely on taste, smell, hearing, and touch. She also teaches them about convenience items that make cooking easier but do not compromise quality -- items like freeze-dried mushrooms that reconstitute beautifully, and frozen onions.

In all her classes, Preuss teaches how to make food look attractive. ``I emphasize not just the business of eating every day but of dining,'' she says.

Preuss's interest in offering classes for people with special needs was sparked by a telephone call from the representative of a group of learning-disabled people seeking a recommendation of someone who could teach them about food. Preuss volunteered to do the teaching herself, ``because the school was running well and I wanted to expand my horizons.''

Other well-known cooks have volunteered to support her efforts. Flo Braker, author of ``The Simple Art of Perfect Baking,'' plans to travel from California to participate in the programs, and Bert Greene, author of ``Greene on Greens,'' has taught a class for the hearing-impaired.

Having all his instructions mediated through a sign interpreter was a new experience for this seasoned teacher.

``The oddest thing about teaching those who cannot hear is the lack of immediate response,'' Mr. Greene says. ``Quips fall like leaden souffl'es. No matter what technique I demonstrated or which gem of culinary wisdom I imparted, all eyes were riveted in one direction -- not at me but toward my silent collaborator.''

After a half hour of this one-way communication, Greene had a brilliant idea.

``Reaching down the counter, I encircled the signer's waist so she was forced to my side during the rest of the class. The students applauded this move with unrestrained good humor,'' he says, ``and from then on they closely watched every move I made.''

Preuss's interest in food dates back to the childhood years she spent in Europe, where her businessman father represented the US State Department at trade commission shows.

At 20, after graduating from the University of California at Berkeley, Preuss moved to Paris. She studied at Le Cordon Bleu cooking school and then worked in fashion design in Europe, New York, Boston, and California. ``Wherever I went, I cooked,'' she says.

In 1981, when she settled in New Jersey, where she lives with her three children, Preuss decided to concentrate on food, and she developed the Cookingstudio with Kings Super Market.

Preuss also conducts educational programs for the market's workers, including the greengrocers and butchers.

Preuss's enthusiasm contributes to her success as a teacher of groups with special needs.

``She communicates with people through her love of food and cooking,'' says Barbara Robinson, chief of audiology at Overlook Hospital in Summit, N.J., who has coordinated classes for the hearing impaired.

``Food is concrete, and everyone can relate to it. It's almost like a universal language.''