Then I stood up straight for a moment, breathed in the sharp sea smells of iodine and salt, and looked around at the vividly beclouded sky, at the endless hills in one direction and the endless water in another, at the black-faced lambs skittering across grass-topped dunes and the speckled harriers lofted high above our heads by the wind, at the wisp of Northern Ireland's Antrim coast faintly visible on the horizon—and it became clear to me that just by being here and breathing in the atmosphere, literally and figuratively, I was probably learning more about Islay malt—the best whisky in the world, in my book, and certainly the least compromising one—than any distillery tour could teach me.

The island of Islay (pronounced ''EYE-la''), the southernmost of the Inner Hebrides, is about 80 miles west of Glasgow, facing the peninsula of Kintyre on the Scottish mainland. It is an awkwardly shaped, geographically varied island—a thick stump of land with a bump of a plateau at the southern end and a long appendage jutting down from its northwestern corner. The beaches of Islay are broad, often merging into marshy salt flats, and it is not uncommon to see shaggy Highland cattle moping across expanses of damp sand. In the interior, there are vast acreages of flat farmland and peat moor. In the spring (when I visited), the heather is mute (it flowers in fall), but the gorse—known locally as whin—is everywhere in bloom, illuminating the landscape with its intense, dark yellow blossoms. (They smell, improbably, of coconut.)

The first known inhabitants of Islay were farmers from the mainland, who arrived around 4300 B.C. They may have cultivated barley here, but the process of converting it into strong alcohol, through fermentation and then distillation, didn't reach Islay until the 16th century—when it was most likely brought across the water by Irish monks. Today, barley is raised on Islay only for animal feed, and grain for whisky making is brought in—but the island has a seemingly inexhaustible supply of two other substances essential to the fashioning of malt whisky: freshwater and peat (see box below). It also has generous access to a third highly influential flavoring component: the sea. ''To say, as some do, that the ocean doesn't affect the whisky is nonsense,'' says Mike Nicolson, manager of the celebrated Islay distillery Lagavulin. ''Our warehouses are all smack by the ocean, and while the maritime influence may be invisible, it's strong and constant.'' The whisky barrels absorb the air and sea spray, and inevitably a ghost of salt remains to haunt the alcohol. In addition, the peat that smokes and flavors the malted barley before it is fermented contains compressed, partially carbonized salt grass and iodine-rich seaweed. Though there are certainly differences between them, Islay malts thus end up having in common what artist, author, and whisky lover Ralph Steadman has called ''a strong salt-sprayed, aye, aye, Cap'n, seaweedy flavour.'' They taste and smell, that is, of salt and iodine and kelpy sweetness (besides the smoke and yeast and grain that all malts reveal). What I found myself surrounded by that afternoon at Loch Gruinart wasn't just background color, then; it was Islay malt itself.

Most fo the whisky made in Scotland is based on wheat and other cereals, distilled in massive devices known as patent, or continuous, stills, and is comparatively neutral in character. Malt whisky, on the other hand, is made from malted barley and distilled in copper pot stills (like those used for cognac and armagnac), and it has not only character to spare but strong regional identity. Blended scotch is a mix of grain and malt whiskies (with malt in the minority). When the unique yield of Scotland's hundred-plus malt distilleries is bottled unblended, it is known as single malt.

Most distilleries now use malted barley from commercial processing plants around Scotland. Seven distilleries, however, still produce a portion of their own malt—among them, two on Islay: Bowmore and Laphroaig. The grain is soaked in water, then spread out to germinate—a process whereby insoluble starch becomes soluble starch. To stop the germination and add flavor to the finished whisky, the malted barley is next dried over smoky peat fires in huge kilns. Then the dried malt is ground to grist and mixed with hot water in huge round tubs called mash tuns. A portion of the soluble starch in the malt converts to sugar, yielding a sweet liquid called wort. This is drained off, cooled, dosed with yeast, and fermented for about two days. (''The fruit flavors in whisky and the floral aromas—sweet peas, roses, primroses—all come from the yeast,'' says Jim McEwan.) The fermented wort, or wash (basically sweet, smoky-tasting beer), is distilled twice in copper stills. The resulting alcohol is then aged in wood (see Foreign Wood)—rarely for less than ten years or more than 25, though some rarities can be up to 40 years old.

There are now six distilleries on Islay—a lot for an island with fewer than four thousand inhabitants. (A seventh Islay distillery, Bruichladdich, has been mothballed since 1995; an eighth one of recent memory, Port Ellen, in the town of the same name, is closed for good—though its gutted buildings still stand, and its whisky can still be found.)

The best-known Islay whisky internationally is undoubtedly Laphroaig, whose current American advertising campaign stresses the love-it-or-hate-it reaction it tends to evoke in first-time drinkers. Iain Henderson, Laphroaig's distillery manager, waxes eloquent about the purity and sophistication of his facility: ''We use an amalgamation of technologies from all over the world. A combination of old and new.'' Volumes, times, and temperatures are controlled by computer, and there is much stainless steel where other distilleries might use wood. What makes each malt whisky unique, he continues, are water, malt specifications, the size and shape of the wash still [in which the first distillation takes place], the quality of the aging casks, and the location of the aging cellars. ''It's an accident of geography that we can make and mature this kind of whisky here.''

Indeed, a not dissimilar malt is made by Laphroaig's immediate neighbor, Lagavulin—which is becoming increasingly popular, thanks in large part to an aggressive marketing campaign by its owner, the massive United Distillers & Vintners: United, whose roster includes some 27 whisky distilleries from every production area in Scotland (including another one on Islay; see below), packages Lagavulin as one of its six Classic Malts, and thus the whisky finds itself on many of the best bars in America. (It is the best seller of the six.)

Laphroaig, Lagavulin, and a third distillery, Ardbeg, are practically next to each other, along a stretch of Islay's southern coast just east of Port Ellen. The three make a dramatic sight, especially from the air (the tiny turboprops that fly regularly between Glasgow and Islay pass right overhead): Set at the water's edge and framed by craggy, black, seaworn rocks, the distilleries are whitewashed to an Andalusian purity, with whisky-blackened roofs and malting kilns rising up like stout chimneys, their pagoda-shaped ventilator hoods on top. Until last summer, though, Ardbeg was idle and in disrepair. Now, under the ownership of the Glenmorangie company, it's come to life again and is producing more of its acclaimed whisky—certainly the most potent and concentrated in ''aye, aye, Cap'n'' flavor of any single malt. ''The character of Ardbeg is so strong that it greatly influences any blend it's added to,'' explains Edwin Dodson, a veteran distillery manager brought in to supervise the start-up, ''so when there was enough for immediate blending, production stopped. Now, we hope that more and more might be able to be absorbed into the single malt market.''

The original Caol Ila distillery (the name, pronounced ''cole-EE-la'', means ''Sound of Islay''), was torn down in the 1970s and replaced with a modern, rather anonymous facility—and its owner, United Distillers again, has used it as a kind of utility player, to produce whisky of whatever character is needed at the time for blending in the firm's many brands. Currently, the style is light for an Islay, but delicate and complex. Besides being sold as a single malt, Caol Ila is used in such famous whiskies as Johnny Walker Black Label and Bell's 8-Year-Old. ''I am told that they can use quite a high percentage without dominating the blend,'' David Hardy, the distillery's operations manager, told me rather dryly.

The gray stucco Bunnahabhain distillery, remote even by Islay standards, at the end of a long, narrow, winding country road near the island's northern tip, produces what is surely the least Islay-like of Islay malts—lightly peaty, with a hint of iodine character revealed only if you really look for it. It is an elegant malt, though, and, says John Mac- Lellan, Bunnahabhain's brewer, whisky lovers doing the distillery tour often find their way to this remote location. ''Touring is getting to be quite a hobby,'' he notes. ''Some people collect bottles. Some ask us to sign their guidebooks. The really decent people, of course, just buy some whisky and take it home and drink it.''

Bowmore, said to be the fastest growing of all single malt brands in Britain, offers a wide range of malts of varying ages and specifications. Jim McEwan was manager of the Bowmore distillery—in the town of the same name, which is the island's capital—when I first met him in New York City a few years back. Now, he's general manager of Morrison-Bowmore Distillers, Bowmore's parent company—in turn owned by Japanese whisky giant Sun-tory. When McEwan shows visitors around Islay, the tour becomes, for him, at least in part an exercise in autobiography: Across from the main gate of the distillery, for instance, is the island's sole outpost of the Royal Bank of Scotland. ''I was born in the house that used to be right there,'' he says. On a road in the middle of the island, he points off to a large house hidden behind a hedgerow. ''That's where my grandmother used to work as a housekeeper,'' he recalls. We pass a sober-looking stone church on the outskirts of Port Charlotte; ''My wife and I were married there.'' At the little Museum of Islay Life in Port Charlotte, he proudly shows me a picture of himself as a robust young cooper with a '70s haircut, building a barrel at Bowmore. He worked at almost every other job at the distillery before rising to executive level.

One of his first jobs, McEwan tells me one evening as we dine at the delightful little Bridgend Hotel on the mussels we've gathered that day (followed by chicken breast stuffed with haggis in a Drambuie cream sauce), was mucking out the sheep pen at the local slaughterhouse. He was paid, he claims, in sheep heads—which he would load into a baby carriage and sell from door to door for five pence apiece for the making of sheep's-head soup, one of the glories of Scottish home cooking. This may well be true—but McEwan is a great storyteller with an impish sense of humor: Bowmore gave one of its old bonded storage warehouses, next to the distillery, to the town some years ago for use as a health club with an indoor pool—the only one on the island. The water in the pool circulates through the distillery tanks, McEwan tells me, thus heating it at no cost to the municipality. Every Thursday, he says, a group of local senior citizens known as the Sunshine Club comes there to swim. ''The day I retire,'' he continues with a grin, ''I'll switch a valve…''