What Becomes a Salad Most? : Olive Oil: Producers have seized the opportunity to promote it as more healthful than other salad oils, and Americans are using more of it than ever.

The national olive oil business has been growing at a phenomenal rate--about 20% a year. Why the sudden surge? “In the early days,” explained Jaan Sulg, vice president of operations at Pompeian Inc., a brand available in the United States since 1908, “the country was not in a health mode, and manufacturers made no effort to advertise olive oil.”

But when scientists began touting monounsaturated oil as a cholesterol reducer, importers and manufacturers of olive oil seized the opportunity to promote their product. Suddenly the words “no cholesterol” appeared on product labels (actually no vegetable oil contains cholesterol or ever has). And manufacturers began to develop olive oil in new ways.

Consider “light” olive oil, an alternative to the more pungent pure olive oil. “Light” olive oil consists of a blend of virgin olive oil and refined olive oil with impurities removed. Bertolli, which produces 70% of the light olive oil in the market today, introduced it to attract the large group of consumers who believed that olive oil was healthful but had reservations about its naturally strong flavor. Apparently the tactic worked. “ ‘Light’ olive oil has been the most successful product in our 125-year-old history,” said William C. Monroe, president of Bertolli U.S.A. Ltd.

The firm recently unveiled an olive oil spray made with a blend of olive oils and no alcohol or additives. Bertolli will also introduce a new olive oil called Robusto, a lighter-colored and lighter-flavored extra-virgin olive oil. Neither product is available in Los Angeles as of this writing.

About 95% of the olive oil exported to the United States comes from the Mediterranean region. Italy and Spain are top exporters, followed by Tunisia, Greece and France. California is a relative newcomer to the olive oil market.

Among the handful of olive oil companies in California, Santa Barbara Olive Co. in Santa Barbara, the third-largest California producer of olive oil, produces cold-pressed and unrefined olive oil, using surplus olives from canneries to make make oil in many flavors. Extra-virgin olive oil and “Geno’s Garlic Nectar” (flavored with garlic from Gilroy) is bottled to sell at gourmet boutiques and specialty shops around the country.

Wente Brothers Winery in Livermore, Calif., makes olive oil from 160 olive trees that were planted in 1880 and already used to make olive oil before the start of World War II. Wente’s olive oil is made with Lucques olives, an olive variety from France. It also makes a mixed olive oil called Oro Misto.

The Napa Valley Olive Oil Co., one of the oldest California-based olive oil manufacturers, also makes olive oil. Its production is small, and only available locally.

When we did a tasting of extra-virgin olive oil at The Times, another California oil, the dark-green Tra Vigne oil from the Napa Valley, was the clear winner. At Tra Vigne restaurant in St. Helena, the oil is served as a prelude to a meal, poured into a small plate to be eaten as a dipping sauce for crusty bread.

Pietro Coricelli, priced at $2.69 for a 16.9 ounce bottle, placed second. Some tasters described Pietro Coricelli as “nutty” and “mild.” For the relatively low price, it is a good bargain.

Santa Barbara Olive Co. extra-virgin olive oil shared third place with Greater Galilee olive oil, made from Israel’s souri olive. Little Israeli oil is exported, most of it being consumed within the region. “I started with a keg last year, and now produce a couple of tons,” said Ehud Yonay, president of the company. The product, which comes in a 12.6-ounce (375-milliliter) bottle, sells for about $8.50.

The Greek brand, Peloponnese, and Bertolli extra-virgin olive oil scored fourth in the tasting. Bertolli is the No. 1 selling oil in the United States.

Pompeian extra-virgin olive oil, Bertolli’s United States competitor, slipped into fifth place.

AN OLIVE OIL PRIMER:

Olive oil is made by grinding the olives, at room temperature, into a heavy paste. This is traditionally done by a large granite wheel, although steel grindstones are also used today. The paste is then spread over stacked straw mats. Steel plates randomly interspersed in the press extract the olive’s liquid, a combination of oil and water. The oil is decanted naturally or by centrifuge, then filtered to remove any major impurities or particles.

Oils are divided into two major categories: virgin and pure.

Virgin oils are natural and unrefined and have not been subjected to manipulation. The oils are extracted through the simple pressing of olives and have a light aroma, rich taste and a yellow to green color. They have a longer shelf life than refined oils.

Extra-virgin olive oil is made from the finest fruit of the olive tree, and the oil is obtained in a single, cold pressing. Before bottling, the oil is gently filtered to remove natural sediments. The acidity of extra-virgin olive oil must be less than 1%.

Fine virgin is an oil of superior flavor and aroma whose acidity is 1.5%.

Virgin oil is smooth in flavor, and acidity is not more than 3.3%.

Pure olive oils have been refined in order to remove impurities, hence the name. The process also reduces acidity and results in a rather bland product. Producers blend virgin or extra-virgin olive oils into pure oil to return flavor, color and aroma that have been lost in the filtering process.

In addition to the filtration to remove natural sediments, pure olive oil goes through a second filtering to lighten color and aroma and lessen acidity.

In the United States, about 70% of bottles labeled olive oil are pure. The acidity of pure olive oil is low: 0.18%.