Exam Focus
- Explain sulfur-containing compounds as a sensory evaluation topic within Specific beer flavor compounds.
- Distinguish hydrogen sulfide, sulfur dioxide, mercaptan-like, vegetal, struck-match, and other sulfur impressions by quality and timing.
- Relate sulfur character to raw materials, yeast metabolism, fermentation, maturation, light exposure, and contamination while prioritizing style and intensity.
Core knowledge
- Hydrogen sulfide can smell like rotten egg; sulfur dioxide can suggest struck match; mercaptans can be onion, garlic, rubber, or skunky.
- Sulfur may arise from yeast strain, fermentation stress, lager fermentation, autolysis, lightstruck reactions, or contamination.
- Low sulfur may be acceptable in some lagers, but harsh sulfur or rubbery notes usually indicate a fault or poor handling.
Study application
Identify the sulfur family and then decide whether it is normal lager yeast expression, light damage, yeast stress, or contamination.
Key Terms
- Hydrogen sulfide
- Hydrogen sulfide can smell like rotten egg; sulfur dioxide can suggest struck match; mercaptans can be onion, garlic, rubber, or skunky.
- Sulfur
- Sulfur may arise from yeast strain, fermentation stress, lager fermentation, autolysis, lightstruck reactions, or contamination.
- Low sulfur
- Low sulfur may be acceptable in some lagers, but harsh sulfur or rubbery notes usually indicate a fault or poor handling.