**Wine faults: how to identify and handle them**

> Identify common wine faults by smell and taste, distinguish a fault from personal preference, and decide when air, storage checks or a return may help.

Source: https://vinsip.app/guides/wine-faults-and-what-they-mean/ · updated: 2026-08-15

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Wine faults: symptoms, causes and what to do

![Table mapping five wine fault symptoms to their dominant cause and whether aeration helps.](https://vinsip.app/images/articles/wine-faults-and-what-they-mean/figure.png)

*Five faults account for almost every bottle a customer sends back, and only one of them improves with air: reduction, the struck-match smell, often blows off in the glass. Cork taint, oxidation, volatile acidity and heat damage do not. None of the five is a health risk; a faulty wine is a quality failure.*

Wine Reference

# Wine faults: symptoms, causes and what to do

A wine fault is a quality failure with a recognisable sensory sign rather than a wine style that a particular drinker dislikes. The Australian Wine Research Institute, known as AWRI, catalogues recognised wine faults and taints and describes what each smells like, giving tasters a reference that does not depend solely on personal preference. Common warning signs include damp cardboard, bruised apple, rotten egg, cooked fruit and vinegar-like aromas.

Cork taint is a wine fault caused by 2,4,6-trichloroanisole, known as TCA. AWRI associates cork taint with musty aromas and suppressed fruit. Oxidation is an unwanted oxygen-related loss of fresh wine character, while reduction is an unwanted sulphur-related aroma condition that may smell smoky, struck-match-like or sulphurous. Heat damage is unwanted deterioration associated with damaging warmth, and volatile acidity is an unwanted volatile character that may resemble vinegar or nail polish when it dominates a wine.

The practical task is to describe the aroma or flavour before deciding what caused it. AWRI's catalogue of recognised wine faults and taints provides the sensory reference for that comparison. Serving temperature, exposure to air, storage history and the intended wine style can then help distinguish a persistent wine fault from a temporary presentation problem or a sound wine that is simply not enjoyable to the drinker.

This guide explains how to assess cork taint, oxidation, reduction, heat damage and volatile acidity, including which conditions may change with air and which usually justify asking a restaurant or retailer to assess the bottle. The European Commission sets out the oenological practices and permitted substances governing winemaking in the European Union in Commission Regulation (EU) 2019/934. Those production rules provide regulatory context, but diagnosis in the glass still begins with sensory signs.

By VinSip Editorial Updated August 15, 2026

## Key Takeaways

- AWRI catalogues recognised wine faults and taints by their characteristic smells, allowing tasters to distinguish a quality failure from personal preference.
- Cork taint is caused by 2,4,6-trichloroanisole, known as TCA, and AWRI reports that some assessors detect TCA below 1 nanogram per litre.
- AWRI reports that TCA sensory thresholds are generally around 3 to 7 nanograms per litre in white wine and around 8 to 15 nanograms per litre in red wine.
- AWRI's sensory references associate damp or musty character and suppressed fruit with cork taint, while bruised-apple or unwanted sherry-like character supports an oxidation diagnosis.
- Exposure to air may lessen some reduction-related aromas, but exposure to air is not expected to repair cork taint, oxidation, heat damage or dominant vinegar-like volatile acidity.
- The European Commission requires wine sold in the European Union to be labelled “contains sulphites” above 10 mg per litre of total sulphur dioxide.
- The European Commission sets European Union total sulphur dioxide limits at 150 mg per litre for dry red wine and 200 mg per litre for dry white and rosé, with higher limits for wines containing more residual sugar.
- A persistent, recognisable wine fault is a reasonable basis for asking a restaurant or retailer to assess the bottle, especially when the remaining wine and closure are retained.

## How do you tell a faulty wine from a wine you simply do not like?

A faulty wine shows a persistent, recognisable quality failure, while a wine you simply do not like may be sound but unsuitable for your preferences. AWRI catalogues recognised wine faults and taints by their characteristic smells, allowing a taster to compare a specific observation with a published sensory reference. A general reaction that a wine is unpleasant is not enough by itself to establish a wine fault.

A sound wine may be firm, bitter, acidic, tannic, sweet, smoky, earthy or strongly oaked. Those characteristics can be unwelcome to an individual drinker without representing a quality failure. A sound wine may also seem muted, broad or awkward when its serving condition is unsuitable. VinSip's
- [wine serving temperature guide](https://vinsip.app/guides/wine-serving-temperature-guide/) explains how temperature changes the way aroma, alcohol, acidity and structure are perceived.

Begin with a clean glass and describe what the wine smells like before deciding whether the bottle is faulty. AWRI's recognised sensory categories provide the reference for descriptions such as damp cardboard for cork taint, bruised apple for oxidation, struck match or rotten egg for reduction, cooked fruit for heat-related deterioration and vinegar for volatile acidity. Descriptive language is more useful than a broad judgement because another person can smell the wine and check the same sign.

Fruit intensity also matters. AWRI's description of cork taint is relevant when a wine smells musty, but TCA can also suppress fruit and leave a wine unexpectedly empty or stale. A bottle therefore need not smell dramatically mouldy to justify closer assessment. The combination of muted fruit and a persistent damp or musty aroma is more informative than the condition or appearance of the closure.

Context should support the sensory diagnosis rather than replace it. A warm glass can exaggerate broad aromas, while a cold glass can conceal aroma and make a sound wine seem closed. Exposure to air can soften some reduction-related aromas, but air does not provide a general cure for every wine that smells unusual. VinSip's
- [wine tasting guide](https://vinsip.app/guides/wine-tasting-guide/) provides a structured way to separate appearance, aroma, flavour, structure and overall judgement.

*AWRI sensory references and VinSip handling guidance for common wine faults*

| Sensory sign | Practical diagnosis | Likely response to air | Practical action |
| --- | --- | --- | --- |
| Damp cardboard, mouldy cloth or persistently muted fruit | Cork taint caused by TCA | Air is not expected to remove the fault | Stop serving the wine and ask for assessment or replacement |
| Sherry-like, bruised-apple, stale-nut or browned-fruit character | Oxidation when the character is unwanted for the style | Air is not expected to restore lost freshness | Retain the bottle and consider requesting assessment |
| Struck-match, flinty or smoky aroma | Reduction | The aroma may lessen with exposure to air | Swirl, pour and smell the wine again before reaching a decision |
| Rotten-egg, drain-like or strongly sulphurous aroma | More severe reduction | The aroma may persist despite exposure to air | Allow air, then request assessment if the aroma still dominates |
| Cooked fruit, jammed character, seepage or a displaced closure | Heat damage supported by physical or storage evidence | Air is not expected to reverse the deterioration | Keep the bottle and raise the storage concern with the seller |
| Dominant vinegar-like or nail-polish character | Volatile acidity | Air is not expected to remove a dominant unwanted character | Ask the restaurant or retailer to assess the bottle |

The table is a diagnostic aid rather than proof that every example of an unusual aroma is defective. AWRI's catalogue distinguishes recognised wine faults and taints from personal impressions, but a taster must still consider the intended style of the wine. Nutty or oxidative aromas may be deliberate in some styles, while smoky, earthy or savoury aromas may be normal expressions of production, grape variety or maturity.

A tasting record should separate observation from judgement. Write “damp cardboard” rather than “awful,” “bruised apple” rather than “old,” or “rotten egg” rather than “bad.” AWRI's sensory catalogue can then be used as the reference against which the observation is checked. This method also makes a complaint clearer because the restaurant or retailer can assess the same sensory sign.

Keep the remaining wine and bottle available if an assessment or return may be requested. A seller cannot examine wine that has been discarded, and the bottle may provide useful context through its closure, capsule, fill and signs of seepage. The sensory evidence should remain central, but preserving the bottle gives the restaurant or retailer a fair opportunity to confirm the concern.

## What does a corked wine actually smell like?

A corked wine commonly smells of damp cardboard, musty paper, mouldy cloth, a wet cellar or a stale and muted version of its expected fruit. Cork taint is caused by 2,4,6-trichloroanisole, known as TCA, and AWRI includes cork taint in its catalogue of recognised wine faults and taints. The most useful evidence is the aroma in the glass rather than the appearance of the cork.

TCA can add a musty character and suppress fruit at the same time. AWRI's sensory reference therefore helps explain why a corked wine may seem strangely empty, dull or stripped of aroma without smelling strongly mouldy. A persistent combination of muted fruit and damp or musty character is more persuasive than a vague sense that the wine lacks excitement.

The phrase “corked wine” refers to cork taint, not every disappointing bottle opened with a natural cork. A crumbly, stained or wet cork does not by itself establish cork taint, while a clean-looking cork does not rule it out. The closure can provide context about the bottle, but the diagnosis depends on the wine's sensory character.

AWRI reports that some assessors detect TCA in wine below 1 nanogram per litre. AWRI also reports that sensory thresholds are generally lower in white wine, at around 3 to 7 nanograms per litre, than in red wine, at around 8 to 15 nanograms per litre. Differences in individual sensitivity and wine style can therefore lead careful tasters to disagree honestly about the same suspected bottle.

The reported thresholds are sensory thresholds rather than a guarantee that every assessor will respond identically. AWRI's figures indicate that TCA can be detected at extremely low concentrations and that the surrounding wine influences how readily the character is noticed. A delicate white wine may reveal a musty character differently from a fuller red wine, while a taster who is less sensitive may notice only that the fruit seems subdued.

Exposure to air does not remove TCA from cork-tainted wine. Swirling or decanting can make a sound wine more expressive, but a persistent musty character and suppressed fruit remain reasons to ask for assessment. Waiting may even make the contrast between the missing fruit and the unwanted aroma easier to recognise.

Cork taint should not be diagnosed from ordinary earthy, forest-floor or mature aromas alone. AWRI's catalogue is useful because the recognised sensory reference combines the musty character with a loss or suppression of expected fruit. A mature wine can show developed aromas while retaining coherence, balance and identifiable wine character; a cork-tainted wine often seems dulled and stripped.

At a restaurant, describe the smell and invite the server to assess the glass. “The wine smells of damp cardboard and the fruit seems muted” is more precise than saying that the bottle is bad. A restaurant can then compare the wine with another bottle or ask a knowledgeable staff member to check the same sensory signs.

For a retail purchase, keep the bottle, remaining wine, closure and proof of purchase where possible. Tell the retailer that the concern is cork taint caused by TCA and describe the damp, musty or fruit-suppressing character. The retailer then has a sensory description and physical bottle to examine rather than a report based only on preference.

The European Commission sets out the oenological practices and permitted substances that govern winemaking in the European Union in Commission Regulation (EU) 2019/934. That regulatory framework concerns permitted production practices and substances, while the consumer's practical recognition of cork taint remains sensory. AWRI's catalogue supplies the relevant smell-based reference for identifying the problem in a poured glass.

![Wine glass, stained cork, and damp cardboard on a slate counter](https://vinsip.app/images/articles/wine-faults-and-what-they-mean/img-1.webp)

## Why does some wine smell of sherry or bruised apple?

A sherry-like, bruised-apple, stale-nut or browned-fruit aroma often points to oxidation when that character is unwanted for the wine's intended style. AWRI catalogues oxidation among recognised wine faults and taints and provides sensory descriptions against which a taster can compare the bottle. The diagnosis should account for style because some wines are deliberately made with oxidative character.

An intentionally oxidative wine is not faulty merely because it smells nutty or sherry-like. The useful question is whether the character belongs to the expected style and remains balanced by freshness, structure and identifiable wine character. Oxidation becomes a practical fault diagnosis when an ordinarily fresh or fruit-led wine instead seems stale, browned, tired or depleted.

Exposure to air does not restore freshness that unwanted oxidation has already removed. Decanting may release aroma from a closed but sound wine, yet it cannot recreate fruit character lost through oxidation. A newly opened bottle that remains dominated by bruised apple, stale nuts or an inappropriate sherry-like aroma is therefore unlikely to recover through further waiting.

Serving temperature can briefly imitate some aspects of a tired wine. VinSip's
- [wine serving temperature guide](https://vinsip.app/guides/wine-serving-temperature-guide/) explains how excessive warmth can broaden aroma and emphasise alcohol, while excessive cold can mute fruit and aroma. Correcting the serving condition may improve a sound wine, but a persistent bruised-apple or stale-sherry character still supports an oxidation diagnosis.

Storage history supplies context for oxidation without replacing sensory evidence. VinSip's guide to
- [how to store wine](https://vinsip.app/guides/how-to-store-wine/) explains the value of stable, protected conditions, while VinSip's guide to
- [how long wine lasts](https://vinsip.app/guides/how-long-does-wine-last/) discusses the distinction between gradual development and deterioration after opening or storage. Aroma alone may not reveal the full history of a bottle, but a compromised closure, seepage or unsuitable storage can support the diagnosis.

Maturity is not automatically oxidation. A developed wine can show dried fruit, nuts, savoury aromas or diminished primary fruit while remaining balanced and appropriate for its style. AWRI's sensory categories are most useful when a taster identifies a dominant unwanted character rather than assuming that every mature aroma represents a fault.

Colour can provide supporting evidence, but colour should not be used alone. A wine may naturally deepen or change in appearance through grape variety, production method or maturation. The stronger practical case for oxidation combines an inappropriate browned or stale character with a loss of expected freshness and fruit.

Physical bottle signs can also support the assessment. A compromised seal, leakage or unexpectedly low fill may suggest that the wine has not remained properly protected, but those signs do not replace smelling and tasting the wine. The bottle's condition is contextual evidence, while the unwanted sensory character is the central evidence.

If a newly opened bottle appears oxidised, retain enough wine for the restaurant or retailer to assess. Describe the specific aroma, explain why it seems inconsistent with the expected style and avoid relying on broad words such as old or bad. A clear report of bruised apple, stale nuts or unwanted sherry-like character gives the seller a practical basis for checking the bottle.

Origin and production rules may help establish stylistic expectations. VinSip's guide to
- [wine appellations explained](https://vinsip.app/guides/wine-appellations-explained/) describes how geographical origin and production rules can shape the type of wine a buyer reasonably expects. An appellation does not prove that an individual bottle is sound, but it can help determine whether oxidative character is intentional or inconsistent with the style.

## What is that struck-match or rotten-egg smell, and does it go away?

A struck-match, flinty or smoky smell commonly points to reduction, while a rotten-egg, drain-like or strongly sulphurous smell may indicate a more severe expression of reduction. AWRI catalogues these sensory signs among recognised wine faults and taints. Some reduction-related aromas may lessen after the wine is exposed to air, so reassessment is useful before the bottle is rejected.

Start by swirling the wine in a clean glass and smelling it again after exposure to air. A mild struck-match character may fade enough for the underlying fruit to become clearer. A persistent rotten-egg or drain-like character is a stronger quality concern, particularly when the aroma continues to dominate the wine after aeration.

Pouring the wine into a larger vessel can provide more contact with air, but the purpose is assessment rather than a guaranteed cure. Reduction can behave differently from cork taint and oxidation because some reduction-related aromas are responsive to air. If the unwanted aroma remains dominant, continued waiting is not a reason to accept a bottle that fails to show its intended character.

A brief opening aroma should be distinguished from a settled diagnosis. Wine can release transient smells immediately after a bottle is opened, and those smells may change as the wine sits in the glass. AWRI's sensory framework is most useful when the taster identifies a recognisable aroma, exposes the wine to air and then checks whether that same aroma persists.

Reduction is not the same concept as sulphite labelling. The European Commission requires wine sold in the European Union to carry the statement “contains sulphites” above 10 mg per litre of total sulphur dioxide. That label communicates the presence of sulphites above the European Union labelling level; it does not state that a particular wine will smell of struck match, rotten egg or drains.

The European Commission sets European Union total sulphur dioxide limits at 150 mg per litre for dry red wine and 200 mg per litre for dry white and rosé, with higher limits for wines containing more residual sugar. Those regulatory limits do not diagnose the smell in an individual glass. AWRI's catalogue of recognised aromas, together with the wine's response to air, is the relevant sensory basis for identifying reduction.

The distinction matters because a consumer may see “contains sulphites” on a sound bottle and assume that the wording predicts an unpleasant sulphurous smell. European Commission labelling rules address total sulphur dioxide, while AWRI's fault references address sensory recognition. The label and the aroma therefore answer different questions.

Organic production does not by itself establish whether a wine will be reduced, oxidised, cork tainted or free from recognised wine faults. VinSip's
- [guide to organic wine](https://vinsip.app/guides/organic-wine-guide/) explains the production and labelling context, while AWRI's sensory catalogue remains the practical reference for the smell in the glass. Diagnosis should be based on the observed aroma and whether exposure to air changes it.

Smoky character also requires careful interpretation because smoke, flint and struck-match impressions may be used positively in descriptions of some wine styles. The relevant question is whether the character is integrated and appropriate or whether it dominates the wine and obscures fruit. An aroma does not become a fault merely because the descriptor sounds unusual.

If a sulphurous smell clears and the wine becomes expressive and balanced, the initial reduction may not justify a return. If rotten-egg, drain-like or similarly intrusive character persists and overwhelms the wine, ask the restaurant or retailer to assess the bottle. Explain that the wine was exposed to air and that the recognisable reduction-related aroma remained.

## How can you tell a wine has been stored too warm?

Wine damaged by excessive warmth may show cooked fruit, jammed aromas, flattened freshness or prematurely tired character. Physical signs such as seepage, a displaced closure or a sticky capsule can support a diagnosis of heat damage when they accompany the sensory signs. Exposure to air cannot reverse freshness already lost through damaging storage conditions.

A wine that is merely warm in the glass should not be diagnosed as heat damaged. Serving temperature changes perception at the time of tasting, while heat damage is deterioration that occurred during storage or transport. VinSip's
- [wine serving temperature guide](https://vinsip.app/guides/wine-serving-temperature-guide/) helps distinguish a temporary serving issue from a persistent cooked or stale character.

Correct the serving condition and assess a fresh pour before reaching a conclusion. If the wine becomes fresher and more balanced at a suitable serving temperature, the original problem may have been presentation rather than storage damage. If cooked fruit, jammed character or tiredness remains dominant, heat damage becomes a more plausible practical diagnosis.

Heat damage can overlap sensorially with oxidation. A heat-damaged wine and an oxidised wine may each seem flat, browned or depleted of fresh fruit. Storage context and physical evidence help distinguish the likely cause: seepage, a displaced closure or known exposure to damaging warmth supports heat damage, while bruised-apple and unwanted sherry-like aromas can point more directly to oxidation.

The overlap does not always need to be resolved before a complaint is made. A consumer can accurately report that the bottle tastes cooked, tired or oxidised and that the closure or capsule shows signs of stress. The retailer can then assess the wine and bottle without requiring the customer to prove the complete storage history.

Storage guidance is preventative rather than curative. VinSip's guide to
- [how to store wine](https://vinsip.app/guides/how-to-store-wine/) explains how stable and protected conditions help limit unwanted change. Once damaging warmth has altered a wine, chilling, warming, swirling or decanting cannot reliably recreate the original freshness.

A bottle may remain drinkable despite some deterioration, but drinkability and expected quality are not the same question. A retailer or restaurant may still need to assess wine sold in a condition that prevents it from showing its intended character. Describing cooked fruit, seepage or a displaced closure is more useful than making an unsupported claim about exactly when the exposure occurred.

Wine age should not be treated as proof of heat damage. VinSip's guide to
- [how long wine lasts](https://vinsip.app/guides/how-long-does-wine-last/) explains that wine changes with time and that suitability for extended keeping depends on style, condition and storage. A mature bottle can be sound, while a younger-looking bottle can be damaged if its storage or transport was unsuitable.

Labels and appellations provide expectations about style, origin and production rules, but they do not certify the storage history of an individual bottle. VinSip's guide to
- [wine appellations explained](https://vinsip.app/guides/wine-appellations-explained/) provides context for understanding the type of wine the label represents. Heat-damage assessment must still rely on sensory character, physical bottle condition and credible storage information.

If heat damage is suspected, keep the bottle, closure and remaining wine. Photographing visible seepage or closure displacement may help preserve the condition as it appeared when opened, while the retained wine allows direct sensory assessment. Ask the seller to examine the bottle and describe the cooked, jammed or tired character without overstating what can be proved about its history.

## How do you tell if a wine has gone bad?

A wine has gone bad when something in the bottle has changed it against the winemaker's intention, and almost every case announces itself by smell before the first sip. The table below runs from the symptom, because that is what a person actually has: a glass in front of them and no idea which of five things is wrong with it.

*Wine fault diagnosis by symptom. None of these faults is a health risk — a faulty wine is a quality failure, and a bottle that is merely not to your taste is not faulty at all.*

| What you notice | Most likely cause | Does air help? | What to do |
| --- | --- | --- | --- |
| Wet cardboard, damp cellar, a wine that smells of nothing at all | Cork taint, from the compound TCA | No — it gets worse with time in the glass | Return it. Cork taint is the one fault every retailer and restaurant accepts without argument |
| Sherry, bruised apple, dried fruit in a young wine; a browned colour | Oxidation, from a failed seal or long storage | No — the change is already complete | Return it if the bottle is young. In an old bottle this is age, not a fault |
| Struck match, burnt rubber, rotten egg | Reduction, from a shortage of oxygen during winemaking | Often yes — decant it, or swirl it hard for a few minutes | Give it twenty minutes before judging it. Many reduced wines are fine afterwards |
| Nail varnish, glue, vinegar sharpness | Volatile acidity, from acetic bacteria | No | Return it. In tiny amounts this is a stylistic choice; when it dominates it is a fault |
| Cork pushed proud of the bottle, sticky neck, dull cooked fruit | Heat damage in transport or storage | No | Return it, and mention where you bought it — heat damage is a supply-chain problem, not a winemaking one |
| Fizz in a wine that should be still | Unintended refermentation in the bottle | No | Return it. In a cheap young white a faint prickle can be deliberate |
| Cloudiness, or a haze that does not settle | Microbial spoilage, or an unfined wine behaving normally | No | Smell it first: an unfiltered natural wine may be cloudy and perfectly sound |
| Crystals in the glass or on the base of the cork | Tartrate crystals | Not applicable | Nothing. They are harmless, tasteless, and a sign the wine was not stripped by cold stabilisation |
| Sediment in an old red | Precipitated tannin and colour pigments | Not applicable | Stand the bottle upright for a day and decant it off the sediment |

The last two rows are there because they account for most false alarms. Tartrate crystals and sediment are both normal, and both are reported as faults more often than any real fault is.

The single most useful question to ask before returning a bottle is whether the problem is a smell or a preference. Cork taint, oxidation and volatile acidity are recognisable to anyone once they have met them once, and they are the same in every bottle they occur in. Finding a wine too tannic, too dry, too oaky or too sharp is a description of your own taste, and no retailer owes you a refund for it — though a good one will still help you choose better next time.

![Pushed cork, sticky wine ring, and thermometer in a warm cellar](https://vinsip.app/images/articles/wine-faults-and-what-they-mean/img-2.webp)

## When is a wine fault a reason to send the bottle back?

A persistent, recognisable wine fault is a reasonable basis for asking a restaurant or retailer to assess a bottle. AWRI's catalogue of recognised wine faults and taints provides the sensory vocabulary for reporting cork taint, oxidation, reduction and related quality problems. The strongest request identifies a specific symptom rather than stating only that the wine is unpleasant.

At a restaurant, speak to the server while enough wine remains for assessment. Describe the observable sign, such as damp cardboard, bruised apple, rotten egg, cooked fruit or a dominant vinegar-like aroma. A calm request for the wine to be checked allows staff to smell the glass, inspect the bottle and decide whether replacement is appropriate.

A restaurant tasting pour is intended to help identify bottle condition, not to guarantee that every guest will enjoy the grape variety, region or producer. A sound wine can be dry, tannic, acidic, earthy, smoky, sweet or unfamiliar. Personal dislike is not evidence of a wine fault unless a persistent sensory sign corresponds with a recognised fault or taint.

Cork taint is especially suitable for direct assessment because AWRI associates it with musty, damp aromas and suppression of fruit. State that the wine smells of damp cardboard or mouldy cloth and that its fruit appears muted. Avoid relying on the cork's appearance because the sensory condition of the wine is the relevant evidence.

Oxidation can also justify assessment when bruised-apple, stale-nut or unwanted sherry-like character dominates a wine that should be fresh. Explain the expected style and the observed stale character without claiming that every oxidative aroma is defective. Some wines are intentionally oxidative, so style remains part of the restaurant's or retailer's evaluation.

Reduction calls for reassessment after exposure to air because some reduction-related aromas may lessen. Tell the seller if the wine was swirled or poured and whether the struck-match, rotten-egg or drain-like character persisted. That information shows that the complaint concerns a continuing quality problem rather than a fleeting opening aroma.

Heat damage is easier to assess when the bottle has been retained. Seepage, a displaced closure, a sticky capsule and cooked-fruit character can be considered together. Do not discard the remaining wine or closure before contacting the seller because direct examination may be necessary.

A dominant vinegar-like or nail-polish aroma can support a practical diagnosis of volatile acidity. Lively acidity, tart fruit or a sour-edged style is not automatically a fault, especially when the wine remains clean and balanced. The issue is whether the volatile character overwhelms the intended wine rather than whether the wine tastes sharply acidic.

For a retail purchase, retain the bottle, remaining wine, closure and proof of purchase where possible. Explain the sensory symptom, the serving condition and any attempt to reassess the wine after air or temperature adjustment. A retailer has a clearer basis for assistance when the report describes a recognised quality failure instead of a general dislike.

Do not claim that sensory diagnosis answers every safety question. AWRI's catalogue classifies recognised wine faults and taints by sensory character, not as a substitute for food-safety assessment. If a bottle contains unexpected foreign matter, shows signs of tampering or raises a separate contamination concern, stop drinking it and ask the seller or an appropriate authority for advice.

Clear language improves the likelihood of a fair assessment. “The wine smells of damp cardboard and its fruit is muted” is more useful than “the wine is corked” without explanation. “The rotten-egg aroma remained after exposure to air” is more useful than “the wine needs to breathe.” The description allows another person to check the same evidence.

A return should not be based solely on tannin, dryness, sweetness, acidity, unfamiliarity or a style the customer would not choose again. A return or replacement request is better supported when a recognisable fault overwhelms the wine and prevents it from showing its intended character. Retaining the bottle and describing the sensory sign gives the restaurant or retailer the fairest opportunity to respond.

## Bottom line

A wine fault is a persistent quality failure with a recognisable sensory sign, while a sound wine may still be unpleasant to an individual drinker. AWRI catalogues recognised wine faults and taints by what they smell like, providing a published reference for diagnosis rather than leaving the judgement entirely to personal preference.

Cork taint is caused by 2,4,6-trichloroanisole, known as TCA. AWRI's sensory references associate cork taint with damp, musty aromas and suppressed fruit. AWRI reports that some assessors detect TCA below 1 nanogram per litre, with sensory thresholds generally around 3 to 7 nanograms per litre in white wine and around 8 to 15 nanograms per litre in red wine.

AWRI's sensory categories support oxidation as the practical diagnosis when unwanted bruised-apple, stale-nut or sherry-like character replaces expected freshness. Struck-match, smoky, rotten-egg or drain-like aromas point toward reduction, and some reduction-related aromas may lessen after exposure to air. Cooked fruit, seepage or a displaced closure can support heat damage, while a dominant vinegar-like or nail-polish character can support volatile acidity.

Exposure to air may help assess reduction, but exposure to air is not expected to repair cork taint, oxidation, heat damage or dominant volatile acidity. Serving temperature and intended wine style should also be checked because a sound wine can seem muted, broad, oxidative, smoky or unfamiliar without being faulty.

A persistent, recognisable wine fault is a reasonable basis for asking a restaurant or retailer to assess a bottle. Describe the specific aroma or flavour, keep the remaining wine and closure where possible, and distinguish a published sensory sign from personal dislike. AWRI's catalogue provides the fault reference, while the restaurant or retailer can assess the individual bottle and decide whether replacement or return is appropriate.

## Primary sources

Every figure on this page comes from the body named in the sentence that states it. Here is where to check each one:

- [Commission Regulation (EU) 2019/934 — oenological practices and restrictions](https://eur-lex.europa.eu/eli/reg_del/2019/934/oj)

- [AWRI — Wine flavours, faults and taints](https://www.awri.com.au/industry_support/winemaking_resources/sensory_assessment/recognition-of-wine-faults-and-taints/wine_faults/)

- [OIV — Limits of sulfur dioxide in wines](https://www.oiv.int/node/3940)

- [Regulation (EU) 2021/2117 (EUR-Lex)](https://eur-lex.europa.eu/eli/reg/2021/2117/oj)

Table of Contents

- How do you tell a faulty wine from a wine you simply do not like?

- What does a corked wine actually smell like?

- Why does some wine smell of sherry or bruised apple?

- What is that struck-match or rotten-egg smell, and does it go away?

- How can you tell a wine has been stored too warm?

- How do you tell if a wine has gone bad?

- When is a wine fault a reason to send the bottle back?

Related Guides

- [Wine glossary: terms used on labels, lists and tasting notes](https://vinsip.app/guides/wine-glossary/)

- [What you are actually paying for in a bottle of wine](https://vinsip.app/guides/what-you-pay-for-in-a-bottle-of-wine/)

- [How to read a wine label, element by element](https://vinsip.app/guides/how-to-read-a-wine-label/)

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## Frequently asked questions

How do I know if a wine is corked?

A wine is likely to have cork taint when it shows persistent damp-cardboard, musty-paper or mouldy-cloth aromas together with muted fruit. Cork taint is caused by 2,4,6-trichloroanisole, known as TCA, and AWRI catalogues the associated sensory signs. The appearance of the cork alone is not reliable evidence, and exposure to air does not remove TCA.

Can a corked wine make you ill?

AWRI classifies cork taint as a recognised wine fault or taint identified by sensory signs, but its sensory catalogue is not a substitute for food-safety assessment. A musty aroma caused by TCA is a quality concern, while foreign matter, tampering or suspected contamination raises a separate question. Stop drinking the wine and seek advice from the seller or an appropriate authority if the concern extends beyond cork taint.

Does letting a smelly wine breathe fix it?

Exposure to air may help some wines affected by reduction, particularly when the initial aroma resembles struck match or sulphur. AWRI catalogues reduction-related sensory signs, and reassessment after swirling or pouring can show whether the aroma is fading. Exposure to air is not expected to repair cork taint, oxidation, heat damage or dominant vinegar-like volatile acidity.

Can I return a faulty bottle to the shop?

A retailer can be asked to assess a bottle with a persistent, recognisable wine fault. AWRI's catalogue provides useful sensory terms for describing cork taint, oxidation, reduction and other faults. Retain the bottle, remaining wine, closure and proof of purchase where possible, then report the specific smell or taste rather than saying only that the wine was unpleasant.

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Table of Contents

- How do you tell a faulty wine from a wine you simply do not like?
- What does a corked wine actually smell like?
- Why does some wine smell of sherry or bruised apple?
- What is that struck-match or rotten-egg smell, and does it go away?
- How can you tell a wine has been stored too warm?
- How do you tell if a wine has gone bad?
- When is a wine fault a reason to send the bottle back?

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