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Wine fault

Brettanomyces (Brett)

A spoilage yeast producing barnyard, plaster and sticking-plaster aromas. Genuinely divisive: a fault to some, complexity to others.

Genuinely argued about4-ethylphenol and 4-ethylguaiacol

What you notice

Smell

  • Smells of farmyard, horse blanket, leather or animal
  • Smells of sticking plasters, antiseptic or medicine
  • Smoky, bacon or clove-like notes

Taste

  • A thin, metallic or drying finish, with the fruit diminished

What it is

Brett is the most genuinely contentious entry in this section. At low levels it contributes savoury, leathery complexity that many drinkers value, particularly in traditional Rhône, Bordeaux and Rioja. At high levels it strips fruit and dominates the wine with barnyard and antiseptic notes.

Sensitivity varies widely between individuals, and so does tolerance. Two experienced tasters can genuinely disagree about whether the same bottle is complex or faulty.

WineHQ takes the position that low-level Brett is a stylistic matter and high-level Brett is a fault, and states plainly that where the boundary sits is a judgement rather than a measurement.

It has become less common as winery hygiene has improved, which some drinkers regret and others welcome.

What causes it

  • The yeast *Brettanomyces bruxellensis* metabolising compounds present in the wine, producing volatile phenols.
  • Favoured by low sulfur dioxide levels, higher pH, residual sugar and warm cellars.
  • Old barrels are a common reservoir, since the yeast colonises the wood and is very hard to remove.

Can I fix it?

No — nothing will fix it

No, and it is worth being clear that this is a matter of taste as much as of fault.

What you can do

  • Nothing can remove it from the bottle.
  • If you find it unpleasant, this producer or this style may simply not suit you.
  • It is not a manufacturing defect in the way cork taint is, so returning a bottle for Brett is a much weaker claim.

What does not work

Published because a reader holding a spoiled bottle has usually already been told to try one of these. Correcting the specific wrong advice is more use than stating the right answer beside it in silence.

Aeration
The ethylphenols are not volatile in the way sulfides are. Time in a decanter does not reduce them, though it may bring up fruit that distracts from them.
Filtering at home
Removes yeast cells, not the compounds they already produced. The smell is not the yeast.

Is it safe to drink?

Not a safety problem

Unpleasant, not harmful. You can drink it; you may not want to.

Yes. Brettanomyces is a spoilage yeast rather than a pathogen, and it is present at some level in a great many red wines including several very famous ones. Nothing it produces is a health concern; whether you enjoy what it produces is a genuine matter of taste, which is why this page is filed as contentious rather than as a fault.

Can I take it back?

Usually not. Unless the wine is overwhelmingly affected, Brett falls closer to a matter of style than to a defect, and many producers do not regard low levels as a problem at all.

Sources

Sources consulted

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