fusel oil

1 9.5

A strong-smelling oily mix of alcohols left over when making drinks like whiskey

noun
/ˈfjuːzəl ɔɪl/

Specialized

: aceite fusel

Excessive fusel oil in whiskey can lead to undesirable tastes and aromas.

Examples

During fermentation, some alcohols convert into fusel oil, impacting the final product's quality.
The distillation process produced a significant amount of fusel oil, which can affect the flavor of the spirits.
It must be the low fusel oil content.

The Color of Money (1986)
You're tasting low fusel oil content.

The Color of Money (1986)

Surface Forms

fusel oil singular

fusel oils plural

Morphology

fusel + oil

The compound is compositional: 'oil' commonly denotes an oily product derived from whatever precedes it, and 'fusel' refers to a type of alcohol/by-product of distillation; therefore 'fusel oil' transparently means an oily substance originating from fusel. Although 'fusel' is a relatively specialized and rare lexeme, if a B1 learner knows both constituent meanings the overall sense is predictable from standard English noun+oil formation.

Etymology

The noun fusel oil comes from the German word 'fusel' meaning 'bad drink' and the word oil for its oily feel. It was the smelly, oily leftover when people made spirits, so today fusel oil means the rough extra alcohols that give a harsh taste.