sulphur dioxide

21 mg per capsule

Sulphitic, like a struck match or young white wine”

Certified beer flavour standard used to train professional beer tasters to recognize and scale the intensity of sulphitic character. Sulphur dioxide is produced by lager yeasts (but not by ale yeasts) during fermentation. Some brewers add this substance to their beers in one form or another as an antioxidant. Sulphites keep beer fresh during storage. They also impart a distinctive sulphury note to beer.

Food grade | free from sensory impurities | extensively tested | safe to smell and taste.

Flavour cards

Flavour standard information

Technical specification

The best way to detect sulphur dioxide (SO2) 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
21 mg per capsule
The flavour threshold of sulphur dioxide in beer is 3 – 7 mg / l. The precise value depends on the concentration of carbonyl compounds such as acetaldehyde in the beer.
Acetaldehyde is produced by lager (but not by ale or wheat beer) yeast during fermentation. It may be added to beer as an antioxidant in some markets.

Professional beer tasters can confuse the flavour of sulphur dioxide with the following:

  • Ethanethiol
  • Dimethyl trisulphide
  • Hydrogen sulphide
Sulphites keep beer fresh during storage. They affect the flavour intensity of many beer aldehydes. When added as an antioxidant, they impart a distinctive sulphury character to fresh beer.
CAS registry number
The CA registry number of sulphur dioxide is 7757-83-7.
Other names
  • sulfur dioxide
  • sulfurous acid anhydride
  • fermenicide powder
  • fermenticide liquid
  • sulfurous anhydride
  • sulfurous oxide
  • SO2
  • sulfur oxide
  • oxosulfane oxide
About 1% of tasters are sensitive to sulphites and may suffer an allergic reaction. Don't take any risks with your assessors' health. Check whether they have any allergy issues relating to sulphites prior to providing samples containing SO2 to them.
Threshold distribution
Capsules per pot
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
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Sulphur dioxide beer flavour standard
earn 6 points