Almost every complaint about wine labels comes down to one split. Some labels tell you what is in the bottle. Others tell you where it came from and expect you to know what that implies. Neither is hiding anything; they are answering different questions, and once you can tell them apart, a shelf of unfamiliar bottles stops being random.
The two conventions
A New World label leads with the grape. Cabernet sauvignon, Napa Valley. Sauvignon blanc, Marlborough. The grape is the headline because these countries built their industries when varietal labelling was the norm, and because their appellation systems draw boundaries without dictating what may be planted inside them. An American AVA restricts nothing but the source of the fruit.
An Old World label leads with the place. Chablis. Sancerre. Barolo. Rioja. The grape is usually absent, because the appellation law already fixes it. Chablis must be chardonnay. Sancerre must be sauvignon blanc for the white and pinot noir for the red. Barolo must be nebbiolo. The place name is a compressed statement about grape, yield, method and often minimum ageing, and it carries far more information than a grape name does, provided you can decode it.
This is why one hour of study pays off more with French and Italian wine than with anything else. There are perhaps thirty place names that cover most of what you will meet, and each one you learn removes a whole shelf from the unknown.
The words that actually mean something
Reserve, on a New World label, usually means nothing at all. It is not legally defined in the United States, Australia or New Zealand, and a producer may use it on any wine. In Spain and Italy it is the opposite: Reserva and Riserva specify minimum ageing in barrel and in bottle, and those minimums differ by region.
Estate bottled, mis en bouteille au château or au domaine, means the producer grew the grapes and made the wine on their own property. It is a real claim and a useful one, because it rules out anonymous bulk buying.
Old vine has no legal definition anywhere except in a few voluntary schemes. Barossa's Old Vine Charter sets 35 years, and South Africa's Old Vine Project certifies vines of 35 years and older with the planting date on the seal. Elsewhere it is a marketing word, though usually an honest one.
Vintage is the year the grapes were picked, not the year the wine was bottled or released. In the United States a stated vintage requires 95 percent of the fruit from that year, or 85 percent if the label carries only a state or county name.
Alcohol tells you more than you expect
The alcohol figure is a compressed weather report and a style signal. Sugar in the grape becomes alcohol in the wine, and sugar comes from sun. So 12 percent on a red suggests a cool region or an early pick, and a lighter, fresher, higher-acid wine. Fifteen percent suggests heat, full ripeness and a rich, warm, weighty wine.
For whites the same logic holds, with an added wrinkle. A German riesling at 8 percent is not underripe: fermentation was stopped deliberately, so the unfermented sugar stayed in the bottle. Low alcohol in a German riesling usually means sweetness. Low alcohol in a dry white from anywhere else usually means a cool climate.
What is not on the label
Sweetness is the biggest gap. Very few countries require it to be stated, and the German Prädikat words, Kabinett, Spätlese, Auslese, describe ripeness at harvest rather than sweetness in the glass. A Spätlese can be fermented completely dry. The word to look for on a German or Austrian bottle is trocken, which means dry. On a Loire bottle it is sec for dry, demi-sec for off-dry and moelleux for sweet.
Additives are also mostly absent. Contains sulphites appears because it is legally required above a low threshold, and it is not a warning about anything unusual: sulphur dioxide is a preservative used in almost all wine, and fermentation produces some regardless. The fining agents used to clarify wine, which may include egg white, milk protein or isinglass from fish, are rarely declared, which is why vegan certification exists.
A practical order for reading one
Look at the place first. If it is a country or a very large region, expect a simple wine. If it is a small named zone, someone thought the distinction was worth making.
Then find the grape, on the front or the back. If it is not there and the place is European, look the place up once and you will never need to again.
Then read the alcohol, which sets your expectation for weight. Then the vintage, which matters most in marginal climates and least in reliably warm ones. Everything else on the label, the heraldry, the medals and the tasting note written by the marketing department, is decoration.