2-isobutyl-3-methoxypyrazine

Technical specification

Assessment

The best way to detect earthy taints from 2-isobutyl-3-methoxypyrazine in beer is as follows. Without covering the glass, swirl the beer to release the aroma. Take a single short sniff. Repeat as necessary.

Amount of flavour per capsule

60 ng per capsule

Threshold

The flavour threshold of 2-isobutyl-3-methoxypyrazine in beer is 20 ng / l.

Origins

2-Isobutyl-3-methoxypyrazine is imparted to beer through use of contaminated brewing liquor, rinse liquor or dilution liquor. The source of the taint is growth of microorganisms in the water supply.

Confusions

• Not yet known

Importance

2-Isobutyl-3-methoxypyrazine imparts an earthy taint to beer. It is associated with a high degree of consumer rejection. Beers contaminated with 2-isobutyl-3-methoxypyrazine described by consumers as ‘chemical’ ’ or ‘contaminated’.

CAS registry number

The CAS registry number of 2-isobutyl-3-methoxypyrazine is 24683-00-9.

Other names

• 2-methoxy-3-(2-methylpropyl)pyrazine
• isobutyl methoxypyrazine
• 3-isobutyl-2-methoxypyrazine
• galbanum pyrazine
• 2- methoxy-3-(2-methyl propyl) pyrazine
• 2-methoxy-3-(2-methylpropyl)pyrazine
• 2-methoxy-3-isobutyl pyrazine
• 2-2-methyl propyl-3-methoxypyrazine

Remarks

Methoxypyrazine taints can be caused by several compounds, of which 2-isobutyl-3-methoxypyrazine is only one. Water treatment practices should remove the methoxypyrazine prior to use.

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