Gas Chromatographic Determination and Pattern Recognition Analysis of Methanol and Fusel Oil Concentrations in Whiskeys

A more efficient determination of methanol and fusel oil in 4 types of whiskeys was accomplished using gas chromatography and temperature programming. Carbopack C with 0.2% Carbowax 1500 (Supelco, Inc., Bellefonte, PA) produced baseline separation of 13 aliphatic alcohols containing 5 carbons or less. A comparison of methanol and fusel oil concentrations between various types of whiskeys Indicates that bourbon and sour mash whiskeys contain considerably more fusel oil (275 ± 1 2 and 265 ± 5 mg/100 mL, respectively) than blended and scotch whiskeys (47 ± 5 and 114 ± 7 mg/100 mL, respectively). All concentrations were corrected to 100 proof. A statistical pattern recognition analysis of the data showed that fusel oil components (1-propanol, 2- methyl-1-propanol, 2-methyl-1-butanol, and 3-methyl-1-butanol) and methanol could be used to distinguish between bourbon-sour mash, blended, and scotch whiskeys. Bourbon and sour mash whiskeys were indistinguishable by fusel ollmethanol analysis. A significant increase in methanol content occurred In bourbon and sour mash whiskeys after bottles were opened and reseaied for up to 58 months; fusel oil content remained essentially unchanged.