The six traits

Every wine on Earth is an argument between six traits: sugar, acid, tannin, alcohol, body and the finish. None of them needs a trained palate. Each one shows up in a specific place, on a schedule, and once you know the addresses you can read any glass put in front of you.

Sweetness

“dry” just means the yeast finished dinner

Sweetness arrives first, on the very tip of your tongue, within about a second. What you're detecting is residual sugar — whatever the yeast left on its plate — counted in grams per litre. Bone-dry sits under 1 g/L. Dry runs 1 to 10. Off-dry, 17 to 35. Sweet, 35 to 120. Dessert wines climb from 120 to 220, which is jam with a licence.

Two traps. First, “dry” on a label can legally hide about half a teaspoon of sugar per glass, and plenty of commercial reds use exactly that trick to feel plush. Second, perception is relative: the same sugar tastes sweeter in a low-acid wine, because nothing is pushing back. Sweetness and acidity sit on opposite ends of a seesaw.

Sparkling wine has its own ladder, and it was clearly named out of spite:

The label says	Sugar	Translation
Brut Nature	0–3 g/L	Bone-dry — nothing added
Brut	up to 12 g/L	Dry; most Champagne lives here
Extra Dry	12–17 g/L	Sweeter than Brut. Yes, really.
Demi-Sec	32–50 g/L	Properly sweet — cake territory
Doux	50+ g/L	Dessert in a flute

When in doubt, run the nose-pinch test. Block your nose and touch the wine to the tip of your tongue. Real sugar tingles there even with the nose out of action. If the tingle vanishes, the wine is dry and your nose was fooling you — vanilla, for instance, smells sweet and tastes bitter.

Acidity

if your mouth waters, that's acidity talking

Acidity is the mouth-watering axis. You feel it under the tongue and along the jawline, where saliva pools a few seconds after you swallow — your body is quite literally rinsing the acid out. The more your mouth waters, the higher the acidity. That's the whole measurement.

On paper, wine sits between pH 2.5 and 4.5 — lemon-to-yoghurt territory — and pH is logarithmic, so each point is ten times the acidity of the last. Cool climates and early picking keep acid in the grape; heat burns it off. In the glass, high acid reads as “fresh”, the quality that makes you want a second sip before the first is finished. No acid reads as flab.

The vocabulary is a ladder. Crisp, racy, nervy: good, and increasingly excited about it. Tart, austere: someone got carried away. Flabby: the acid never showed up, and the wine lies in the glass like warm juice.

Tannin

the same chemistry that turns hide into leather

Tannin is the one people misname, because it isn't a flavour at all. It's a texture. Tannins are polyphenols from grape skins, seeds and stems — and from new oak barrels — and what they do in your mouth is strip proteins straight off your tongue. That drying, grippy sensation is the same chemical reaction that tans animal hide into leather. Every sip of Barolo tans you, very mildly.

If you want the feeling without the wine, over-steep a black tea. That furry grip across the mid-tongue and gums is pure tannin. Grape tannin and oak tannin behave differently, too: grape tannin can run from silk to firm leather, while oak tannin is harsher and more bitter — which is why winemakers ration new barrels, and why used barrels give almost none.

Quality words: fine-grained, velvety, chewy — all compliments, in ascending order of muscle. Astringent and green are complaints. Tight is a hedge; it often just means the wine is young and the tannins haven't relaxed yet. And tannin is why big reds love steak: tannin binds fat and protein, so every bite of entrecôte softens the next sip. The steakhouse cliché is chemistry.

Alcohol

swirl, tilt, count the tears

Yeast ate the sugar; alcohol is the receipt. You feel it as warmth at the back of the throat, sliding down after the swallow. Warmth is fine. Burning is not — a wine that burns is “hot”, and hot is a flaw, not a personality.

The bands: under 11.5% is low, 11.5 to 13.5 is medium, above 13.5 is high (Wine Folly draws the high line at 15%, but by that point we're splitting hairs and slurring them). Alcohol does two jobs beyond the obvious: it carries aroma up and out of the glass, and it builds body.

Party trick: swirl the glass, tilt it, and watch the legs — the tears streaking down the inside. Alcohol evaporates faster than water, which drags liquid up the wall of the glass and sends it weeping back down. Physicists call it the Marangoni effect; use that at a dinner party at your own risk. Thick, slow legs suggest higher alcohol. Guess the ABV out loud, then check the label. I'm right about two times in three, which is enough to look clairvoyant.

Body

skimmed milk vs whole milk

Body is the odd one out: not a measurement but a sum. Alcohol plus sugar plus tannin plus extract — everything dissolved in the liquid — adds up to a physical weight in the mouth. The classic calibration is milk. Skimmed milk is light-bodied; whole milk is full-bodied. Same category, different heft, and you'd never confuse them with your eyes closed.

Hold on to this one, because matching the weight of the food to the weight of the wine is chapter seven's opening move. Light dish, light wine; rich dish, rich wine. Most pairing wisdom is that sentence wearing a bow tie.

The finish

A sip has three acts: the attack (the first impression — sweetness, fruit), the mid-palate (where acid and tannin take over) and the finish (whatever stays after you swallow). Cheap wine tends to have a hole in the middle: a bright hello, then nothing, then a short goodbye. Great wine changes profile two or three times across the sip and keeps talking for twenty seconds or more after it's gone.

One more instrument, free of charge: after swallowing, exhale through your nose. Aromas drift up the back corridor to your olfactory bulb — retro-nasal smelling — and you catch a second broadcast, often different from the first. The finish is where wine earns its price. Length can't be faked, and no back label has ever mentioned its absence.

When the six hold hands

So how do you judge the whole? Three words. Balance: no trait shouting over the others — acid propping up sugar, fruit cushioning tannin, alcohol staying in its lane. Complexity: how many distinct things you can find, and whether they keep changing. Typicity: does the wine taste like what it claims to be — does the Chablis actually taste of Chablis?

Balance is the non-negotiable. A simple, balanced wine is a pleasure; a complex, unbalanced one is an expensive argument. When the six traits hold hands, you stop noticing them individually and the wine simply tastes right. That's the target — and the rest of this course is really the story of how the traits got there.

next: where all of this comes from