What is the difference between decanting and aerating?

In English, "decanting" often covers both actions, which creates confusion. In the wine world, though, there are really two distinct techniques with opposite goals.

Aerating (sometimes called "breathing") is about giving a young wine a burst of oxygen. You pour it fairly vigorously into a wide-bottomed carafe, splashing it around to maximise contact with the air. This softens grippy tannins, blows off any reductive (sulphur-like) aromas, and lets the fruit and spice open up. Young Cabernet, Malbec, Syrah, and Nebbiolo are prime candidates. Think of it as waking the wine up.

Decanting (in the strict sense) is about separating an old wine from its sediment — those fine particles of polymerised tannins, pigments, and tartrate crystals that settle at the bottom of the bottle over years. You pour very slowly, often over a candle or light, into a narrow-necked vessel, stopping the moment you see sediment creeping toward the neck. Then you serve promptly, because old wines are fragile and too much air can cause them to fade in minutes.

The preparation matters too. If you're planning to decant an old bottle, stand it upright for 24–48 hours beforehand so the sediment collects at the bottom.

The classic mistake? Pouring an old Burgundy into a big wide carafe and leaving it for an hour — by the time you pour, the delicate aromas of truffle, leather, and dried flowers have evaporated. Equally, there's no point in gently decanting a two-year-old Malbec — it has no sediment and it needs air, not protection from it.