Wine is the term for the alcoholic product of the fermentation of grapes. Grapes will naturally ferment without any additional sugar, and need not be inoculated by yeast in order for fermentation to start.
The history of wine stretches back nearly 8,000 years to the region in and around Georgia, in the south Caucasus. Archaeological evidence has shown wine residues in pottery jars, and ampelographic studies on 110 varietals of modern grapevines seem to point to a common ancestor somewhere in Georgia. Other regions in the world are famous for wine production, but not as far back as Georgia: Egypt, Greece, India, and China have been making wine for thousands of years.
It was the Roman Empire, though, who spread both vineyards and the knowledge of winemaking throughout Europe. Romans borrowed viticultural knowledge from both the Greeks and the Carthaginians, refined key concepts, then spread winemaking technology along with the Empire as far north as England. The Romans also developed the concept of wines coming from a particular place, with Falernian, Alban, and Caecuban being among famous (and expensive) sites.
As grape vines will grow in places where cereal and other crops cannot, at first, the Romans planted hillsides and places with poor soil. With the eruption of Mount Vesivius (near Naples, a major winegrowing area) in 79 AD, stocks of wine decreased dramatically. This led to cropland being planted with grapes in an attempt to stabilize wine production. When the loss of cropland led to famine, Emperor Domitian issued an edict forbidding the planting of new vineyards in the Roman Empire, and forcing the uprooting of roughly half of what vineyards existed. It wasn't for nearly 200 years that this edict was reversed by Emperor Probus in 280 AD.
The conversion of the Roman Empire to Christianity did nothing to slow down wine consumption. In fact, the necessity of having wine for Mass led to viticulture and winemaking knowledge being protected by the church after the fall of the Empire and for hundreds of years later. Major winegrowing regions were reclaimed by monasteries: Burgundy and the Rhine being two centers for the religious production of wine. Many monasteries walled off certain vineyards that grew grapes of particular quality -- today, these are called "Clos", and are scattered throughout France, with Clos Vougeot in Burgundy, the Clos Ste Hune in Alsace, and Clos Fourtet in Bordeaux being examples of walled vineyards.
Today, vineyards exist and wine is made from the southern tips of South America and Africa to the deserts of Australia, China, Canada, England and Germany. Just about everywhere the grape vine can grow, it is grown.
Grapevines fall into two major families that are used to produce wine: Vitis vinifera and Vitis labrusca. Vitis Vinifera includes all the major European varietals: Cabernet Sauvignon, Chardonnay, Riesling, Merlot, Grenache, and Sauvignon Blanc are all Vinifera grapes. Most of the Vinifera family is decended from Muscat, Vitis Labrusca vines are native to the United States, and are typically crossed with Vinifera vines to make hybrids, usually for disease resistance. Examples of Labrusca grapes include Concord, which has the classic Labrusca "foxy" flavor profile. Some common hybrids include Vidal Blanc, Chambourcin, and Baco Noir.
In the 1860's, a root louse called Phylloxera was inadvertently imported into France in some ornamental plants from the United States. In a thirty year timespan, phylloxera destroyed most of the vineyards of France, forcing major changes in the Cognac region, Bordeaux, and Champagne. Very few European regions were spared the destruction -- phylloxera cannot live in sand or rock, so a lot of the Mosel, for example, is free of phylloxera. Many things were tried to kill the louse, from flooding the vineyards to injecting poisons, but Thomas Munson, a Texan, discovered that if Vinifera vines were grafted to Labrusca rootstock, the louse could not feed from the roots. Today, most vines planted around the world are grafted to stop phylloxera.
Many variables affect the final flavor profile of wine. The type of soil, climate, and microclimate combine to produce a difficult to explain term called terroir - a 'sense of place" that says that Mosel Riesling has high minerality from the slatey soil, as does Champagne from the chalk. Muscadet, which is grown near the Atlantic ocean, tends to taste like seashells. On the human side, vineyard managers and winemakers must decide not only what to grow, but what clone of the grape (Pinot, for example, has hundreds of clones, each with a different character), then decide when to harvest.
Once the grapes are in the winery, more decisions must happen. Here, a winemaker judges the grapes, crushes them, then can decide to use native yeast or cultured, to ferment in stainless steel or oak or concrete, how long to ferment and age the wine, and how to age it. The wine is then filtered (or not) and bottled.
Wine comes in a rainbow of colors — everything from completely clear and water-pale to the blackest, inky looking color imaginable. Wines are red, salmon, amber, orange, purple, and violet. Some are cloudy, and some are fizzy. Sometimes, the carbonation inherent in all fermentation is intentionaly kept in the bottle, making sparkling wines, of which the most famous is Champagne.
The flavors in wine are incredibly complex. First and foremost, no one really knows how we smell anything at all. Smell shouldn't work from a physiological perspective. People have taken swings at the problem, but no one can agree on the mechanism, unlike sight, hearing or vision. Second, the sense of smell bypasses a lot of conscious thought — it is a primal sense that resists being broken down and rationalized. Wine can smell like anything, but a large part of the trick is to turn the little voice in the back of your head that says 'Wine can't smell like that!' off. Wine can smell like fruit, flowers, rocks, mushrooms, vinyl shower curtains, monks singing, a mountaintop, or dryer sheets.