Level 3 · Wine & Spirits Exam Prep
Wine Faults
Identification and causes of common wine faults encountered in professional practice.
Topics covered
- Cork taint (TCA)
- Oxidation
- Volatile acidity
- Brettanomyces
- Reduction
Quick Revision
- TCA: damp cardboard = cork contamination
- Oxidation: sherry-like, stale, brown
- Reduction: sulphur, rubber, rotten egg
- VA: vinegar/nail varnish = acetic acid
- Brett: barnyard, band-aid, medicinal
- Refermentation: unexpected bubbles in still wine
Key Facts for the Exam
- TCA (corked wine): musty damp cardboard smell; caused by chlorine-contaminated corks + fungi
- Oxidation: stale, flat, brown apple/sherry notes; caused by excess O₂ exposure
- Reduction: sulphur/rubber/rotten egg smell; caused by insufficient O₂ during winemaking
- Volatile acidity (VA): vinegar/nail polish (acetic acid/ethyl acetate); high levels = fault
- Brettanomyces (Brett): barnyard, medicinal, band-aid, smoky; low = complexity; high = fault
- Refermentation in bottle: unexpected bubbles in still wine; caused by incomplete fermentation
Level 3 Exam Tips
- 1.TCA = corked = damp cardboard/wet dog. Do NOT confuse with other sulphur or acidic faults.
- 2.Reduction is FIXED by aeration (open the bottle, decant, swirl) — often correctable.
- 3.Brett is controversial: low levels add complexity (leather, spice); high levels are a fault.
- 4.VA is normal at low levels — only becomes a fault when it dominates and tastes like vinegar.
Common Exam Mistakes
- ✗Saying corked wine has cork fragments — corked refers to TCA chemical contamination of the cork
- ✗Thinking reduction is permanent — it can be resolved by exposing the wine to air
- ✗Confusing Brett (biological, barnyard/medicinal) with VA (volatile acidity, vinegar notes)
Related Topics
Frequently Asked Questions
- How do I identify a "corked" wine?
- A corked wine has been contaminated by TCA (trichloroanisole) — a chemical compound that creates a musty, damp cardboard, or wet newspaper smell. The wine will also taste flat and devoid of fruit character. It has nothing to do with cork fragments in the wine. TCA contamination can occur at very low concentrations that completely mute the wine's aromas.
- What is Brettanomyces and is it always bad?
- Brettanomyces (Brett) is a type of wild yeast that can develop in wine. At low levels it adds complexity — leather, farmyard, and spicy notes that some winemakers consider desirable. At high levels it dominates the wine with unpleasant medicinal, band-aid, and barnyard aromas. It is widely found in traditional Bordeaux and some Rhône wines. Whether it is a fault depends on its intensity and your perspective.