STILL IN his tuxedo from the Bartenders' Ball the night before, John Kerry of Forman Brothers liquor wholesalers was manning the open bar at last Sunday's opening of the East-South Regional Restaurant Exposition. The timing of the Exposition could have been better; besides the Bartenders' ball preoccupying a major subgroup of the event's participants, the Sheraton-Washington Hotel -- where the Exposition was held -- had hosted a buffet for 2,300 the night before. And, the Salon of Culinary Arts had fewer entries this year than last April; that had been a more convenient month for chefs to devote those endless hours of preparation.

Still, dozens of entries filled the Salon and hundreds of commercial displays filled the Exposition hall. The eating and drinking reached its usual annual pitch of revelry, and the top entries in the Salon of Culinary Arts were as breathtaking as ever. This competition, open to professionals and amateurs, is the primary public showplace for the artistry of Washington area chefs, as well as the preliminary for the American Culinary Federation's Culinary Olympics Team. Individuals and teams work for weeks -- and traditionally, all night before the judging -- preparing buffets and pastry displays to be judged by elaborate guidelines for their composition, preparation, presentation and difficulty.

For the public, the remarkable characteristic of the entries -- besides their beauty and precision -- is that they are made totally of food. Thus, Patrick Mussel's totally realistic green-slatted park bench and its cinderblock wall were all sugar. Adolf Rehm's antique-style picture frame, which looked like dozens of gilded museum frames you may have seen, was bread dough, as was his miniature roadster. His porcupines' quills were almonds, his coral reef was salt. The bronze Art Deco background on which Terry Teplitzky's saddle of pork rested was aspic colored with coffee grounds. Rebecca Russell's figurines could have been mistaken for Hummel porcelains, but they were almond paste. And Ron Fusek's vases and boxes were sugar pastillage filled with long-stem roses of pulled sugar. It took an experienced eye to recognize the chrysanthemums as turnips, the stags as tallow, the truffles as crab meat rolled in black cavier. Chocolate was having a hey-day this year: chocolate biplane, chocolate roadster (roadsters were also a strong trend), chocolate baskets and a chocolate imperial guard on a horse. The latter, prepared by Patrick McDonnell, was a favorite of the public, but was eliminated from the competition because it was on a plastic support. Even the foods that looked like just what they were -- Klaus Helmin's saddle of veal, for instance -- were fascinating for the precision of the slicing and the lining up of the slices, not to mention the colorful and delicately wrought garnishes, all painted to a shine with aspic.

This year's entries included no grand pastry buffet and only one grand buffet, but there were more student entries than ever. Three entrants -- Adolf Rehm, Klaus Helmin and the Four Seasons Hotel team -- won gold medals, which will put them in good positions for the Olympics competition. In addition to awards in each category, overall awards were given to Ann Amernick (Best Piece of the Show), Adolph Rehm (Most Original Piece), Klaus Helmin (Judges Award), Four Seasons Hotel (Grand Prize), Cao Nguyen (Grand Prize for Apprentices) and Eva Hunt (2nd Overall Prize for Apprentices). p

The food in the Salon of Culinary Arts was to look at, not to eat; the food in the Exposition hall, which was open to the restaurant trade but not the public, was to eat but seldom much to look at. And the pitch, as well as the food, was not meant to be for public consumption.

The Kwik Snak People were selling machines used to batter-coat and grill nearly anything, from hot dogs to cheesecake, and thereby allow a restaurant to charge, as they put it, $5.50 for flambe cheesecake that had a 25-cent food cost. Energy-saving was even more of a watchword than laboror or money-saving at the equipment booths. And one display was aimed at life-saving: a gadget for diners who are choking.

Booth after booth was demonstrating unidentifiable fried bits of things; in such a context, a booth with a mini-field of alfalfa sprouts looked like a vacation. But two alfalfa-sprouts booths across from each other were more than that: an oasis.

Some of the good news in this year's show was fresh shrimp from Key West, Fla., and macadamia nut ice cream from Haagen Dazs. Irish coffee was a key theme: Bassetts ice cream, made with Jameson Irish Whiskey, on the cold end; Irish Velvet, bottled coffee-with-whiskey to mix with boiling water and top with whipped cream, on the hot end. The newest name for a product: landrey's "Genuine "Barbecue, which they also call "Truth in Menu" Bbq. The carried-to-utmost-absurdity product: Lake Eerie Frozen Foods, Inc.'s frozen French fried American cheese cubes. Forman Brothers was doing a big business in Sabra liqueur egg creams and an alcoholic invention called California Root Beer, which has no root beer.

And that summed up the Exposition. In the Culinary Arts Salon, foods were meant to look like something they weren't; in the Exposition hall, all too often the foods were meant to taste like something they didn't. BEST PIECE OF THE SHOW AWARD

Ann Amernick, Elysee Boulangerie FIRST-PRIZE AWARD WINNERS

Individual Cold Food Platters : Adolf Rehm, owner, Rehm's Caterers (also Most Original Piece Award)

Individual Hot Food Platters Displayed Cold : J. Rice Russell, chef, Vie de France restaurant

Individual Pastry Display : Rebecca Russell

Mini Buffet : Klaus Helmin, executive chef, Watergate Terrace restaurant (also Judges Award)

Grand Buffet : Four Seasons Hotel; team captain, Beat Zuttel, sous chef (also Grand Prize)

First Year Apprentices : Amy J. Hotaling, Loew's L'Enfant Plaza Hotel

Second Year Apprentices : Robert Whaley, Watergate Terrace restaurant

Third Year Apprentices : Cao Nguyen, Watergate Terrace restaurant (also Grand Prize for Apprentices)

Student Competition : Michael Michnowski, Culinary School of Washington

Individual Food and Pastry Entry : Terry Teplitzky, chef poissonier, Maison Blanche restaurant