acetic acid

Technical specification

Assessment

The best way to evaluate vinegar-like flavours in cider arising from acetic acid is as follows. Without covering the glass, swirl the sample to release the aroma. Take a single short sniff. Repeat as necessary.

Amount of flavour per capsule

275 mg per capsule

Threshold

The flavour threshold of acetic acid in cider is 90 mg / l.

Origins

Acetic acid is a natural component of apple juice and is produced by yeast during fermentation. Abnormal fermentation, contamination with bacteria or wild yeasts, and excessive exposure to oxygen can all lead to excessive production of acetic acid in cider.

Importance

Acetic acid is present in all ciders and is a major component of ‘volatile acidity’. Concentrations of acetic acid can be elevated in some ciders through use of damaged or rotten fruit and low sulphite additions. At high concentrations acetic acid is an off-flavour which can be indicative of poor factory hygiene.

CAS registry number

The CAS registry number of acetic acid is 64-19-7.

Other names

• ethanoic acid
• ethylic acid
• methanecarboxylic acid
• vinegar acid
• acetasol
• acide acetique
• shotgun
• vinegar

Remarks

The intensity of acetic flavour increases with decreasing cider pH value. Acetic acid can also be produced by malo-lactic bacteria during maturation of cider.

Threshold distribution

Capsules per pot

10