Good wine depends on the variety of grape, when it is harvested and the weather.

Very high sugar content, for one thing. The sugar translates to alcohol content once fermented, and grape juice has much more sugar than, say, apple or cherry juice. This not only helps with the buzz, but extends the longevity of the wine. .

@thorninmud is correct about the sugar content. Another interesting fact is that white-ish blush you see on dark grapes is yeast. Grapes carry their own fermenting agent. There’s no need for the vintner to add anything to the crushed grape juice. Just crush and pour it into barrels. Nature does the rest.

@thorninmud What do you mean it translates? Fermented sugar turns into alcohol or something?

@Blackberry Right. The alcohol is by-product of yeast metabolizing sugar (that’s what fermentation is). Usually the fermentation goes on until all of the sugar has been consumed. That means that the more sugar the juice contains, the more alcohol will be in the finished wine.

If all of the sugar is fermented, the wine is “dry”. To make a sweet wine, the fermentation is stopped before all of the sugar gets fermented.

If you walked in the vineyard, and picked a grape and ate it, you would spit it out. It is not the tasty kind you get at the market.

@filmfann That’s true, but the typical wine grape actually has more sugar than a Thompson seedless grape. It just also has more acidity and tannins, and tough skins. These bring valuable qualities to wine, but they mask the sweetness of the grape for eating purposes.

@thorninmud Ah ok gotcha, thanks :)

@thorninmud Fantastic answers!

Grapes also have a huge variety of phenolic compounds that affect the flavor, color, and aroma of the finished wine. The same type of grape can develop very different flavors depending on the climate where it’s grown and the winemaker’s decisions.

Syrah/Shiraz is a good example. In cooler climates like the northern Rhone valley in France, the grapes take longer to ripen and develop complex flavors. So a northern Rhone wine, like a Crozes-Hermitage, might taste smoky, herbal, or even meaty. If you grow the same grape in a hot region, like the Barossa Valley in Australia, the grapes develop sugar more quickly and the wine might taste like berries, jam, or pepper.

So… I really don’t know too much about the scientific reasons why grapes are better than apples, raspberries, or whatever for making alcoholic drinks, other than that grape wine seem to have a wide range of flavors and characteristics that other fruits don’t have. But I can explain why some wines are so expensive.

It mostly comes down to craftsmanship. A lot of the differences in price come down to how labor-intensive it is to create the wine. When the grapevines are older or grow in marginal regions, the vines use all of their resources to grow fewer grapes and the finished wine is more complex and flavorful. So a lot of the best wines come from very specific sites with insanely high real-estate prices for the best land, or the vines can be decades old. Growers often prune and train the grapes in certain ways for an ideal finished product, or a vineyard may be in a very dry region that calls for controlled irrigation. In colder regions like New York state, Germany, or Canada, some grapes are allowed to rot in a specific way or freeze on the vines before they’re picked, which concentrates all the goodness inside the grapes before they’re made into wine. Or they can pick and choose the grapes by hand, vs. harvesting them by a machine, which makes a difference in price and quality.

Certain phrases on wine labels can be an indicator of quality and price. If a wine is called “old vine,” it means the older vines use all their resources to grow fewer, more intense grapes. If a wine is called “reserve,” it usually means the winemakers have chosen the best grapes from their best sites. There’s no regulation over using those words, so some if it is all marketing. For example, Kendall Jackson Vintner’s Reserve chardonnay is just their regular chardonnay.

Of course, some of the priciness is all about prestige. If a winery gets a lot of good press, they’ll probably jack up their prices a bit. A lot of the fun in learning about wine comes from finding bargains in unusual places.