butyric acid

Technical specification

Assessment

The best way to evaluate butryic notes in beer is as follows. Cover the beer with your hand and swirl the glass to release the aroma. Remove your hand and take a single long sniff. Repeat as necessary.

Amount of flavour per capsule

9.0 mg per capsule

Threshold

The flavour threshold of butyric acid in beer is 3 mg / l. The threshold is lowered by the presence of diacetyl.

Origins

Butyric acid is produced by bacteria during mashing and sweet wort separation, or during sugar syrup production or storage. It is occasionally formed as a result of bacterial spoilage of packaged beer by strictly anerobic bacteria such s Pectinatus and Megasphaera. .

Confusions

Butryric acid can be confused by professional tasters with the following flavours in beer:

• Isovaleric acid
• Ethyl butyrate
• 2,3-Butanedione

Importance

Butyric acid is an off-flavour in beer. The flavour of affected beers can be worsened by the presence of 2,3-butanedione (diacetyl), or improved by ethyl butyrate derived from metabolism of butyric acid by yeast.

CAS registry number

The CAS registry number of butyric acid is 107-92-6.

Other names

• butanoic acid
• butanic acid
• n-butanoic acid
• 1-butyric acid
• n-butyric acid
• ethyl acetic acid
• 1-propane carboxylic acid
• propyl formic acid

Remarks

The intensity of butyric acid flavour increases with decreasing beer pH value.

Threshold distribution

Capsules per pot

10

Legal notices

This product is protected by the following trade marks and patents:

• US Patent no. D679900
• European Community Trade Mark
  Registration no. 009937574
• European Community Trade Mark
  Registration no. 009856527
• US Trade Mark Registration no. 4345057
• US Trade Mark Registration no. 4345056