Prosciutto Is Back From the Ban : Gourmet foods: This Italian ham is as different from most American imitations as French Champagne is from most sparkling wines.

Except for the tall, shuttered windows, the plant doesn’t look that much different than any other moderately successful agricultural concern. But then again, the windows are the key.

For it is these windows that open and shut to capture the cool, dry air that blows in from the surrounding hills of the Po River Valley and permits the small miracle that is the creation of top-quality prosciutto di Parma.

“In our hams, we have only three ingredients,” says Ettore Grisendi, the plant manager, “swine from our fields, salt from the sea and the weather.”

He hesitates and, not without pride, adds “And the experience and skill of our workers.”

After an absence of more than 20 years, true Italian prosciutto--an uncooked, dry-cured ham--is once again available in the United States. Banned in 1967, after reported outbreaks of African swine flu fever in Italy, it was recently reapproved by the USDA for import.

Though there are scores of different prosciutti made in Italy currently, the prosciutto made in this region just outside Parma is the only type available in the United States. It is certainly the best-known. Many cookbooks, in fact, refer to prosciutto generically as “Parma ham.”

So why is true prosciutto di Parma different?

It begins with the pigs, fed partly on the whey left over from the making of Parmigiano-Reggiano cheese. They must be raised in the strictly delimited region, killed at one of only 350 slaughterhouses and processed at one of 214 plants. A little quick math reveals that, with a total regional output of just more than 8 million hams a year, this breaks down to roughly 150 hams per plant per day--making it a truly artisanal product.

It takes this kind of hands-on work to produce the hams. The secret of a great prosciutto’s delicate sweetness and buttery texture lies--as much as any one factor--in the restrained use of salt during the curing process.

The cure takes anywhere from 300 days (the minimum for Italian products) to 400 days (the USDA-mandated minimum for American sale). The hams are, in fact, individually branded with the date processing began. The longer a ham ages, the more buttery the texture--up to a point. Most prosciutto is sold at its best from 400 to 500 days old. Only exceptionally big hams, with high percentages of fat, can take extended aging, and most of those are claimed at the slaughterhouse by important restaurants. A 25-pound prosciutto (the legal minimum weight, post-production, is 12 pounds), aged more than 700 days is the equivalent of drinking an old Burgundy from an exceptional year.

Serve prosciutto sliced as thinly as possible, accompanied only by figs, melons and perhaps shards of true Parmigiano-Reggiano cheese. A luxury product (Italian prosciutto is selling for around $20 per pound, as opposed to $7 or more for domestic), a simple presentation is best. Allow approximately 2 ounces (about four slices) per person.

Most recipes that call for prosciutto use only small amounts--such as a stuffing for tortellini in brodo (soup)--so you can use any scraps left over from trimming the slices. Leftover fat will also add a distinctive note to any sauteed dishes. Also, if your deli owner orders bone-in prosciutto (it is also imported with the bone already removed), ask him to save you the bone. Add it to a soup or a pot of beans. It can be reused six or seven times.

When buying prosciutto, look for size and age. What you do not look for is brand names. There aren’t any. The self-regulating consorzio of ham producers has inspectors who check not only plant sanitation and production, but quality as well. Hams that do not live up to their standards (about 7% to 8%) are discarded. After all, the reputation of an entire industry is at stake, for all prosciutto from Parma is labeled only as prosciutto di Parma.

In Italy, that says it all.

This is one dressy recipe for prosciutto. I’m using it because it is very much like a dish served to me for a very special dinner in the Piemontese town of Alba by Sra. Giacosa at her inn, Cascina Reine. Serve it with a good crusty bread.

INVOLTINI DI ASPARAGI E PROSCIUTTO (Asparagus and Prosciutto Bundles)

18 choice, thick, fresh asparagus spears

1/2 pound Fontina cheese

1/2 pound prosciutto, thinly sliced

6 tablespoons butter

Trim, peel, rinse and cook asparagus until tender-crisp. Do not overcook. Drain asparagus. Set aside to cool.

Cut cheese into thin slices, using swivel-action vegetable peeler or cheese-slicing tool. It doesn’t matter if slices are irregular, as long as they are fairly even in thickness. Divide slices into 6 equal portions.

Divide prosciutto into 6 equal portions.

Take 3 asparagus and place 1 prosciutto slice under them. Take all but 2 slices of cheese from 1 portion of cheese and place it between asparagus stalks. Top with 1 1/2 teaspoons butter. Wrap asparagus, using remaining slices from 1 portion prosciutto. Do not worry if wrap is not perfectly neat, as long as it is fairly even in thickness, not too bunched up in spots. Repeat to make 5 more bundles.

Arrange bundles in single layer in lightly buttered bake-and-serve pan without overlapping. Criss cross 2 slices cheese over each bundle. Dot with remaining 3 tablespoons butter.

Place pan on top rack of oven and bake at 400 degrees 20 minutes until cheese is melted and lightly browned. Remove from oven and let stand several minutes before serving. Transfer to serving plates and baste with pan juices. Makes 6 servings.

(From “More Classic Italian Cooking,” by Marcella Hazan; Alfred A. Knopf, 1978.)