3-methyl-2-butene-1-thiol

Technical specification

Assessment

Lightstruck flavour is best detected by smelling the beer at a distance. Hold the glass at arm’s length and take short sniffs to prevent the risk of adaptation.

Amount of flavour per capsule

100 ng per capsule

Threshold

The flavour threshold of MBT is 4 – 30 ng / l in beer.

Origins

3-Methyl-3-butene-1-thiol is formed in beer as a result of exposure to daylight or artificial light. This initiates a reaction involving hop bitter acids, vitamins and sulphur compounds. Small amounts are also formed in beer production.

Confusions

MBT is sometimes confused with the following flavours in beer

• Sulphur dioxide
• cis-3-Hexenol
• Ethanethiol

Importance

Lightstruck character is an off-flavour associated with exposure to light of beer packaged in clear or green glass. Consumers are very tolerant of this off-flavour. Many successful beers contain MBT at the point of consumption.

CAS registry number

The CAS registry number for MBT is 5287-45-6.

Other names

• lightstruck
• sunstruck
• prenyl mercaptan
• 3-methyl but-2-ene-1-thiol
• methyl butene thiol
• 3-methyl-2-butene-1-thiol
• 3-methyl-2-butenyl mercaptan
• 3-methylbut-2-ene-1-thiol
• prenyl thiol

Remarks

Beers which have been bittered with chemically-modified hop extracts do not develop lightstruck flavour character.

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