"If you really knew what went into hot dogs," we always heard whispered through our childhood summers, "you would never eat them." Dark tales might even turn us to hamburgers for the first few cookouts of the season.

A trip to the Usinger's sausage factory in Milwaukee would have saved a few frankfurter nightmares. Through corridors populated with models of beaming elves, its sausage-mixing rooms are stocked with nothing more sinister than fresh, darkly glistening liver for the braunschweiger, forked into mixing bowls with cloves of fresh garlic and whole bermuda onions. Whole bermuda onions? Whoever peels them?

"We used to have a lady we called the Onion Lady," said Bob Siebecker, a vice president of Usinger's. After more than 20 years, he added, she retired and another onion lady, who also skins the pistachios, took her place.

Who peels the garlic? "It used to be the husband of the Onion Lady," Siebecker said, with a distinctly elfin smile.

Usinger's, which calls itself one of the two largest specialty sausage manufacturers in the country, and whose premium German-style sausages are considered top-of-the-line in Washington delicatessens ranging from Giant's and Safeway's service delis to small carriage-trade food shops, is more home-style than one could imagine a sausage company to be.

A tile-and-marble retail shop leads to the factory itself, whose corridors retain a certain Hansel and Gretel tone. One door reads: "Elves only." And every morning around 9:30 all the employees gather for breakfast in four dining rooms, the "boys" in one, the "girls" in another, as Siebecker put it, with the management meeting in the others. The 150 employees feast on free sausage at breakfast and lunch, over 6 1/2 tons of it a year, which doesn't keep them from buying another 13 1/2 tons for home use. Not only is it an old German custom to feed the employees, but the meals act as an informal quality control program: Nobody can pick up a subtle change in a food better than someone who eats it for two-thirds of his meals.

Milwaukee is a sausage town. "Beer 'n' brat is big here," understated Siebecker. Milwaukee is the kind of town where not only is there a demand for five kinds of liver sausage plus liver loaf and three kinds of headcheese, but where fashionable young couples give wine-and-sausage tastings. White wine with white sausages, red wine with red ones. This is a town where five kinds of sausage are sold at baseball games.

With a large German and East European population, it was an obvious place for the first Frederick Usinger to start selling his liverwurst and knackwurst 102 years ago. And it was a natural to support the expansion to 80 different kinds and 7.8 million pounds of sausages a year, though by now nearly two-thirds of it is sold out of state, in retail stores and by mail. In the early days, the East was Usinger's best out-of-state market. Now the West is, particularly Denver, Chicago and Los Angeles. And by now even supermarkets around the country are selling Usinger's bratwurst, knackwurst, braunschweiger and teawurst, while German delicatessens and other small specialty stores (and the Kroger supermarket chain, which heavily promotes them) emphasize the more esoteric tongue blood sausage and headcheese. While Usinger's sausages tend to be priced 20 to 30 cents a pound wholesale above other sausage, Siebecker maintains that even for Usinger's, "Sausage is a working man's food."

Braunschweiger, a lightly smoked liverwurst, is the flagship sausage of Usinger's, especially in the northern states, where more liver sausage is eaten than in the South. "It is not a packinghouse sausage," boasted Siebecker, showing that it is pale tan, made with no nitrites or other preservatives and with 60 percent liver, which he claims is more than most. Another factor that sets it apart from lesser-quality sausages is that like many Usinger sausages, it has a natural casing, which not only costs more than artificial casings but needs to be stuffed by hand because it is fragile and machines tend to tear it.

"When they started force-feeding hogs," Siebecker explained," the intestines used for casings tended to break," so now for some large-diameter sausages two pieces of intestine must be sewn together to get even, thick casings. "Thick casings make for better sausage flavor," said Siebecker. And natural casings allow smoke to penetrate and thereby flavor the meat.

Another crucial factor in the quality is what goes into those casings. Usinger's buys only fresh meats for its sausages. If you use frozen liver for braunschweiger, said Siebecker, you must also add calcium, usually in the form of dried skim milk; at Usinger's that problem does not arise. Livers are hand-trimmed of their bile ducts so they don't impart a bitter taste. In bolognas, the differences in color from brand to brand depend on the meat and the spices. "We use only natural spices," Siebecker pointed out. And although the government allows 30 percent fat in finely ground sausages such as frankfurters, weiners and knackwurst, Usinger's average 24 to 25 percent.

While the company does use nitrites in all of its red sausages and the 8-ounce chub liver sausages, it leaves them out of the natural-casing braunschweiger--which is sold only at deli counters--because it has only a 7- to 10-day shelf life and will look bad before it is spoiled, explained Siebecker. He argued strongly for the necessity of nitrites, but volunteered that the company has been gradually cutting down on the salt in its products over the last three years. And a new all-veal knackwurst, lower in salt and fat than the old style, is selling well in Milwaukee.

It is not only the ingredients that make for sausage quality, it is also the method. "This plant is not computerized like large ones," Siebecker was proud to tell. He claimed that some plants' computers are tied in with price changes of ingredients so that the amount of meat is automatically adjusted in keeping with the daily price of that meat. At Usinger's, he said, "things are judged by look, feel, taste, smell."

Frankfurters were being made as Siebecker showed the way through the factory. The meat had been chopped by a dozen rotating knives in a revolving steel bowl as spices were gradually sprinkled on by hand. The knives have to be sharpened every four or five days. The ground meat, which is nearly white until the smoking turns it red, went into filling machines, which spurted it out into casings that were fed out by hand, then twisted and tied by hand. It didn't look like fast food. In another room women were poking wooden picks through tiny coils of sausage. These Saussicchens are what Siebecker calls the "oddest item we make", as well as the most laborious. "We don't like to make them," he added. "We try to get people not to buy 'em." At that point one of the women coiling and skewering the cute little oddities spoke up, "Kids love 'em."

Sausages are still an object of pleasure, even to those who handle them 40 hours a week. The things bobbing in boiling cauldrons were pork snouts. "It's the sweetest meat in the hog," insisted Siebecker. To prove his point he continued, "When the guys are stuffing headcheese, some of the snouts don't get into the headcheese." Workers have a propensity to set a bit aside to later salt and pepper and pop into their mouths.

After the cooking--in most cases--comes the smoking, preceded by heat-drying so the the surface will be permeable to the smoke. Usinger's has been buying hardwood sawdust from the same company for a hundred years. Hickory slabs are used for summer sausage. Twenty years ago the company installed an automatic smokehouse, but it so changed the taste and smell of the sausages that Usinger's tore it out and replaced it with another tile-lined brick old-style smokehouse.

Long-smoked sausages are cold-smoked. For the faster, hot-smoked sausages, gas jets are turned on to increase the heat. Frankfurters and wieners are hot-smoked, for three to four hours. Mass producers, said Siebecker, can make a frankfurter completely in 10 minutes. "It takes us a day and a half." Some of the sausages are smoked for two or three days, and even the hams Usinger's buys to sell in its factory store are further smoked on the premises. Then he showed liver loaves baking, insisting that other companies cook them in water. "We make things like you would make them at home," he reiterated.

For the Usinger family it pretty much is home. The third Frederick Usinger runs the factory, and 24-year-old Frederick IV, or Fritz, is now the meat buyer and assistant plant manager, under a sausagemeister who was trained in Germany. Fritz's siblings are all girls, which explains, he said, why the company has not split up like so many family companies; each generation has had only one son. But Fritz's sisters have all worked in the factory, and Deborah is going to manage Usinger's new fast-food restaurant, to be called Wienerworks. Fritz's fiance' Ann Widem, who is from Washington, helped the company to set up its quality control lab, after the couple met in the animal science department of the University of Wisconsin. Fritz is the first technologically trained Usinger, and though, he said, he has learned a lot about sanitation and bacteriology, in his formal education he "didn't even begin to learn the art of sausage making." To start that lesson he worked a summer at Jones sausage factory, since the families are friends.

Thus new and modern influences are infiltrating this kingdom of elves. With a certain restraining spirit. In the conference room is a piece of the gravestone of David Usinger, burgermeister of Oberems, Germany, dated 1685.

Here are a few recipes to make the best of Usinger's 102 "wurst" years.

USINGER'S GERMAN POTATO SALAD (10 servings) 1 pound bacon 5 pounds potatoes, boiled and sliced 1 large spanish onion, minced 3 tablespoons flour 1/2 cup vinegar 1 1/4 cups water 1/2 cup sugar 1 tablespoon salt 1/2 tablespoon pepper

Fry bacon until crisp. Crumble it and add to potatoes and onion in a bowl. Add flour to the hot bacon grease and mix. Add the remaining ingredients to the pan and mix thoroughly until sugar is dissolved and mixture thickens slightly. Immediately pour contents of the pan over the potatoes, onion and bacon and mix thoroughly until most of the juice has soaked into the potatoes.

BRATWURST A LA VERN (4 servings) 2 bermuda onions, coarsely chopped 2 tablespoons butter 1 tablespoon worcestershire 2 tablespoons vinegar 1/2 teaspoon salt 2 tablespoons brown sugar 1/2 teaspoon paprika 12 ounces beer 8 bratwurst

In a heavy saucepan cook onions in butter until lightly browned. Add worcestershire, vinegar, salt, brown sugar, paprika and beer. Simmer 5 minutes. Add bratwurst and simmer 25 to 30 minutes or until done: or grill or fry bratwurst separately and pour sauce over to serve.

SAUSAGE PIE (4 servings) 1 pound bratwurst links 1 cup milk 2 eggs, well beaten 1 cup flour 1/4 cup shredded cheddar cheese 2 tablespoons minced onion

Place sausage links in heavy skillet and bake at 400 degrees for 20 minutes. Combine remaining ingredients and beat well. Remove sausage from oven and pour off all but 2 tablespoons drippings. Arrange links in bottom of pan and pour batter over them. Return to oven to bake 30 minutes longer, or until batter has risen to the top of the pan and is crisp and golden. Cut into pieces and serve immediately with dijon-style mustard.

SAUSAGE STROGANOFF (6 servings) 1 pound smoked polish sausage 2 tablespoons drippings left from saute'eing sausage 1/2 cup scallions, sliced 1 cup sour cream 2 tablespoons tomato paste 1 tablespoon flour 1/2 teaspoon salt 1/4 teaspoon pepper 6 ounces egg noodles, cooked Parmesan cheese, for sprinkling on top

Saute sausages and cut half of the links into bite-size pieces. Saute' onions in drippings until tender. Blend together sour cream, tomato paste, flour and seasonings. Add noodles, sausage pieces and onions. Place in a 2-quart casserole, sprinkle generously with parmesan cheese and top with remaining whole links. Bake at 325 degrees for 25 minutes.