Virginia, the state that has given the nation six presidents and countless military heros, is now "exporting" a unique commodity, "Virginia Whiskey." For the first time drinkers outside the state are being offered a souped-up version (87.7 proof instead of 80) of Virginia Gentleman Bourbon.

It's all very low key, in keeping with the Old Dominion. Only Texas and Florida are targets of a promotion campaign that may be a forerunner of national distribution. A major New York firm, Scheffelin, is handling the marketing.

There are at least two formidable hurdles to clear, however, if Fairfax Country's finest is to become a national favorite. (The A. Smith Bowman Distillary, the state's only bourbon manufacturer, is located in Sunset Hills, which could be called a part of greater Reston.)

The first is economic. The bourbon market (along with scotch and blended whiskey - "brown goods" to the trade) is seriously depressed. Sales for most major brands have declined or barely held even during this decade as "white goods" (especially vodka) and wine have tempted younger tipplers and led older ones to transfer allegiances. Although the Jack Daniels Black Label, of which there isn't very much, is a hot item, selling most bourbons is as difficult these days as selling dollars overseas.

Even in Virginia, where Virginia Gentleman is outsold only by two heavily advertised national brands, Early Times and Jim Beam, tastes are changing. New residents who move into the state are largely unindoctrinated in local tradition. Seeking a wider potential market appears to be necessary as well as prudent.

On the esthetic level, Virginia Gentleman has to overcome the folkloric impression that bourbon flows only from a julep cup-shaped shrine in Kentucky. So linked are the Blue Grass State and bourbon that consumers are assumed to be suspicious of any brand that claims another heritage.

There's really not too much executives of the tiny, family-owned Bowman distillary can do about national drinking habits except hope for a reversal of the trend. They'll be pleased if they can have a decent slice of the diminished pie. Production now is in the 150,000 to 160,000-gallon range and capacity of the plant is only 200,000 to 250,000 gallons. "We'd be tickled pink with a 3 to 4 percent increase," said a spokesman for the distillary.

To obtain that they are resorting to imagery. Advertising and sales efforts in Florida and Texas stress that Virginia Gentleman is "Virginia Whiskey." That term stands out on new labels along with the name itself and on the neck and back labels it's called "The Whiskey of Virginia." Gone is a slogan "The Aristocrat of Them All." A servant holding the tray of bottles and glasses, is gone too from the illustration of men on a lawn before a colonial plantation. The term "straight bourbon whiskey" and the name and address of the distillary have been markedly reduced in size.

The proof has been upped to offer potential consumers out-of-state more bang for their bucks. This runs counter to current thinking in the industry. Bourbon makers have been lowering proof in response to the demand for "lightness." If the proof of Virginia Gentleman goes up in Virginia (it once was 90), so will the price.

Changing the proof of whiskey is not difficult. When bourbon finishes aging it may be as high as 125 proof. Distilled water is added to cut it as desired.

At the Bowman Distillary the bourbon-making process begins when local corn, rye, barley and malt are made into a mash with the addition of water and yeast. By law corn must be at least 51 percent of the mixture. ("Sour mash" is allowed to ferment a day longer than regular - or "sweet" - mash, usually four days instead of three.)

When ready, the mash goes into four-story-high cylindrical fermenters. Resembling rockets on launch pads, they do their work in about 45 minutes. The mash is heated. It produces vapors that condense into alcohol as they are cooled. The whiskey is white as it emerges from the still. Aging takes place in 50-gallon white oak barrels that have been charred inside. The characteristic brown color appears as it ages.

According to Robert E. Lee IV, who manages the distillary's advertising and sales, Virginia Gentleman has several advantages over its Kentucky competitors. The fermentation tubs are made of cyprus wood. The still is copper. The mash is cooked at a lower temperature giving it - Lee contends - more taste. It is aged for four years, two more than the law requires.

But no liquor sales campaign was won on quality alone, so the Bowman Distillary's consulting historian has come up with some propaganda bombshells to lob in the general direction of Kentucky.

The "American" julep was born in Virginia, not Kentucky, he claims. The name bourbon itself comes from Virginia's "Bourbon County" by way of the 18th century French royal family. Futhermore, he points out that the man sometimes credited with being Kentucky's first bourbon maker was a native of Virginia who didn't move west until he was in his 40s. "Any man who is going to make whiskey is going to learn how long before he is 44 years old," Virginia's man says with consummate assurance.

So Virginia Gentleman, waving not a single Confederate flag, has sallied forth. In Florida they've "sedn some encouraging signs," although Texas "has been iffy." All in all after the first six months of this year, sales were reported up 7.6 percent, well above all bourbon's national increase of 1.1 percent.

If the signs are favorable at Christmas, Virginia Gentleman probably will take itself to image-prone California.