dimethyl disulphide

Technical specification

Assessment

The best way to evaluate rotten vegetable, sulphury character 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

230 µg per capsule

Threshold

The flavour threshold of dimethyl disulphide in beer is 75 µg / l.

Origins

Dimethyl disulphide is formed in beer as a result of production of hydrogen sulphide by yeast. If venting of the fermenter is poor (or the fermentation is done under pressure) flavours like this can build up.

Confusions

Professional beer tasters can confuse the odour of dimethyl disulphide with the following:

• Dimethyl trisulphide
• Methional
• Hydrogen sulphide

Importance

Dimethyl disulphide (DMDS) is an off-flavour in fresh beer. It also develops in some beers during ageing in pack. It can also occasionally arise as a taint through use of contaminated carbon dioxide for carbonation of beer. Some describe this flavour as 'dirty sulphur'.

CAS registry number

The CAS registry number of dimethyl disulphide is 624-92-0.

Other names

• DMDS
• dimethyl disulfide
• dimethyl disulfane
• 2,3-dithiabutane
• methyl disulfide
• (methyl dithio) methane
• methyl dithiomethane
• methyldithiomethane
• methyldisulfanylmethane

Remarks

Some systems for recovery of alcohol from yeast produce distillates containing this flavour. These distillates impart this flavour to the beers to which they are added.

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