How to taste wine properly: the five steps and the science behind them
Andi Healey
Web Manager
Hospitality trade • Wine education
How to taste wine properly: the five steps and the science behind them
What actually happens when you taste wine, why each step matters, and how to explain it to a guest.
The five steps of wine tasting haven't changed. What has changed is how we understand and explain them. This guide covers the mechanics behind each stage, the faults to identify before recommending a bottle, and the eight components that determine how any wine actually tastes.
It is also a useful framework for staff training: knowing why each step matters makes it easier to talk about wine with confidence rather than reciting received vocabulary.
The five steps
The systematic approach to wine tasting exists for a reason: it sequences the sensory information in the order it becomes available. Each step activates a different set of receptors and builds on the previous one. Working through them in order gives you a complete picture of the wine before you've committed to a recommendation.
The steps are well known. What is less often explained is the science behind why each one matters, and what to do with the information each one provides.
Sight
Look straight down into the glass, then hold it to the light, then tilt it so the wine rolls toward the rim. The tilt is the step most people skip. It reveals the full colour range, not just the concentrated centre.
Colour gives you three specific data points: grape variety (in broad terms), approximate age, and density. A brownish tinge at the rim indicates age. Bright, vibrant edges suggest youth. A deep purple-black points toward Syrah or Zinfandel; a translucent pale ruby is more consistent with Pinot Noir or Gamay.
Worth knowing for service
Colour-to-grape correlations are becoming less reliable. Climate change and cellar interventions have shifted what many classic varieties look like in the glass. Use colour as a starting hypothesis, not a conclusion. With Nebbiolo in particular, the pale brick-red appearance leads guests to expect a light wine. It is worth flagging this before the bottle arrives at the table.
Swirl
Swirling aerates the wine. Oxygen exposure causes volatile aromatic compounds to vaporise, making them detectable by smell. Without swirling, many of those compounds remain dissolved in the liquid and reach the nose only weakly or not at all.
Swirling also dissipates sulphur compounds that can mask fruit aromas in recently bottled wines. A wine that smells initially of struck matches will often improve noticeably after a minute of aeration.
Technique
Pinch the base of the stem between thumb and forefinger. Keep the base of the glass on the table and draw small circles. A few seconds is sufficient. The legs (or tears) that run down the inside of the glass afterwards indicate viscosity, sugar content, and alcohol level. They are not an indicator of quality, despite what some guests believe.
On decanting
Swirling is a limited substitute for decanting. Pouring wine into a decanter exposes a far greater surface area to oxygen simultaneously. For young, tannic reds, 30-60 minutes in a decanter achieves what swirling cannot. For older, delicate wines, decanting should be brief: extended oxygen exposure can strip the aromatics that took years to develop.
Smell
Around 80% of what we experience as flavour is olfactory, not gustatory. The nose is where most of the work happens. This is not a figure of speech: our olfactory receptors can detect thousands of distinct aromatic compounds, while taste buds register only five basic sensations. Everything we describe as complex, nuanced, or interesting in wine is arriving primarily through smell.
To use it properly: nose close to the rim, several short sniffs, mouth slightly open. The open mouth matters. Taste and smell share neural pathways, and keeping the mouth closed slightly suppresses the full aromatic signal.
What you should be smelling for
The first job is to establish whether the wine is sound. Off-aromas come before any evaluation of quality. After that, the nose builds an aromatic profile across three categories: primary (fruit and floral notes from the grape), secondary (yeast-derived notes from fermentation: bread, biscuit, toast), and tertiary (aged notes from barrel or bottle time: leather, earth, dried fruit, nuts).
Young wines will show primarily primary aromas. The more tertiary notes present, the more the wine has developed. A well-aged Burgundy with pronounced earthy, mushroom, and dried-rose aromas is showing tertiary development that a young wine simply cannot replicate.
Sip
A slightly larger than usual sip, held in the mouth for three to five seconds. This gives time for the wine's temperature to rise slightly, releasing further aromatics through retronasal olfaction: volatile compounds travelling up from the back of the mouth into the nasal passages. This second aromatic hit is why the same wine smells different from the glass and in the mouth.
What the palate adds to the nose is structural information: the perception of acidity, tannin, body, alcohol, and residual sugar. These cannot be assessed by smell alone. A wine can smell balanced and reveal structural problems only on the palate.
Balance is the target. No single component should dominate. If a wine reads as too sour, too astringent, too alcoholic, or too flat, it is unbalanced regardless of its other qualities.
Gently moving the wine around the mouth distributes it across different taste receptors. The tip of the tongue is most sensitive to sweetness; the sides to acidity; the back to bitterness. A wine delivered to only one area of the palate gives an incomplete picture.
Savour
After swallowing, note the finish: how long the flavour persists, whether any new notes appear, and whether the aftertaste is pleasant. A longer finish generally correlates with higher quality, though the quality of the finish matters more than its length. A short, clean finish is preferable to a long, harsh one.
Also note the alcohol: a burning sensation in the throat indicates that the alcohol is unintegrated, which is typically a sign of an unbalanced wine or one that has been served too warm. At 18°C and above, alcohol in red wine becomes the dominant sensation.
The eight components of wine
Every wine can be assessed across eight structural components. Understanding what each contributes makes it possible to explain why a wine works or does not work with a particular dish, and to describe a wine accurately to a guest without resorting to unhelpful language.
Acidity
The bright, mouth-watering sensation primarily determined by grape variety and growing climate. High acidity makes a wine food-friendly (it cuts through fat and refreshes the palate between bites) and also helps wines age well. A Sauvignon Blanc or Riesling will produce noticeably more salivation than a low-acid Chardonnay. Low-acid wines without sufficient fruit or structure to compensate taste flat or flabby.
Tannin
The drying, astringent sensation from grape skins, seeds, and stems, most present in red wines. Tannin is a natural preservative and the main structural reason why tannic reds age well. It also does physical work in food pairing: tannin binds with fat proteins in meat, softening both the wine's grip and the fat's heaviness simultaneously. Without food, high-tannin wines can taste harsh. The same wine alongside a fatty cut of beef is transformed.
Body
The weight and viscosity of the wine in the mouth, on a spectrum from light to full. Body is primarily driven by alcohol content: higher alcohol means more body. A useful reference: light-bodied is closer to skimmed milk, full-bodied closer to cream. Body is the first point of comparison when matching wine to food: a light-bodied wine cannot hold its own against a rich, intensely flavoured dish.
Alcohol
Most still wines fall in the 12-14% ABV range. Alcohol contributes body and warmth; at higher levels it also contributes heat, particularly on the finish. This matters for food pairing: high-alcohol wines amplify the burn of spiced dishes and can overpower delicate ones. There is growing consumer interest in lower-alcohol wines (8-11% ABV), which is worth knowing for menu conversations with health-conscious guests.
Sweetness
Most wines served in a restaurant context are dry (under 4g/L residual sugar) or off-dry (a perceptible but not dominant sweetness). The distinction between fruit-forward and genuinely sweet is one guests regularly misunderstand: a dry Sauvignon Blanc can taste of tropical fruit without containing any residual sugar. The fruit character is from aromatic compounds, not sugar. The practical rule: any dish with sweetness as a primary component requires a wine that is at least as sweet, or the wine will taste bitter and thin by comparison.
Flavours and aromas
The descriptors that constitute a wine's aromatic profile, divided into primary (fruit, floral, herbal), secondary (yeast-derived: bread, biscuit), and tertiary (aged: leather, earth, dried fruit, nuts). These evolve as the wine breathes. A wine that smells closed on opening can show a completely different aromatic profile after 20 minutes in a decanter.
Oak influence
New oak barrels add vanilla, spice, cedar, and toast. The newer the barrel and the longer the contact time, the more oak influence. Neutral oak (older barrels) allows gentle oxygen exchange without adding flavour, contributing texture rather than taste. Unoaked wines aged in steel retain maximum primary fruit. For guests who say they dislike Chardonnay, the question is usually whether they dislike Chardonnay specifically or heavily oaked New World Chardonnay specifically. Chablis is the useful comparison to make.
Terroir
The combined influence of soil, climate, elevation, slope, and aspect on the wine's character. The same grape variety grown in different places can produce wines with almost nothing in common. A Sauvignon Blanc from the Loire and one from Marlborough are both Sauvignon Blanc; the methoxypyrazines that create the herbaceous character are retained in the cooler Loire climate and diminished in the warmer New Zealand one. The result tastes like different grapes. Terroir explains why.
Identifying faults
Fault recognition is a professional skill with a direct service application: a table should never be served a flawed bottle. Knowing what to look for at the smell stage, before a guest has tasted the wine, is the point of the exercise.
| Fault | What it smells like | Cause and notes |
|---|---|---|
| Cork taint (TCA) | Musty, wet cardboard, damp newspaper | Affects roughly 3-5% of wines sealed with natural cork. Unfixable. Replace the bottle. |
| Oxidation | Flat, Sherry-like, stewed fruit | Excess oxygen exposure, typically from a compromised closure or improper storage. Distinct from deliberate oxidative styles like Tawny or Oloroso. |
| Volatile acidity | Vinegar, nail varnish | Acetic acid from bacterial spoilage. Low levels add complexity; high levels are a fault. The nail varnish note (ethyl acetate) is a byproduct of the same process. |
| Reduction (sulphides) | Struck matches, rubber, drains | Common in recently bottled wines. Often disperses with vigorous swirling or decanting. If it persists, the wine is likely irreparably reduced. |
| Brettanomyces | Barnyard, leather, sweat, smoke | A wild yeast present in many wineries. Low levels are considered by some winemakers to add complexity; high levels obliterate fruit character. Divisive rather than universally a fault, but worth knowing as a descriptor. |
On difficult conversations
A guest who has ordered an expensive bottle and believes it is corked is almost always right. The musty, flat character of cork taint is distinctive and rarely confused with anything else. Replacing the bottle without question is the correct response. Arguing with a guest about whether a wine is faulty is not a recoverable situation regardless of who is right.
Every bottle you taste is data. The palate develops through repetition, not reading. Keep notes, compare styles side by side, and back your own judgement on the floor.
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