Acetic Acid
Synonyms: Ethylic acid; Vinegar acid; vinegar; Methanecarboxylic acid; TCLP extraction fluid 2; Shotgun; Glacial acetic acid; Acetic acid, solution, more than 10% but not more than 80% acid
Structure:
CAS RN: 64-19-7 Formula: C2H4O2
Melting point °C: n/a Boiling point °C: 117.9
MW: 60.0524 pKa: 4.75
Importance in coffee: A main acid responsible for perceived acidity.
During roasting: Maximum concentration at light roast.
Other: Colorless liquid or solid with a strong vinegar-like odor detectable at 0.2 to 1.0 ppm. HYGROSCOPIC. Density = 1.0492. Vapor Density = 2.1. Vapor Pressure = 11. Evap rate: 0.97.