Method
- Stir the Scotch, amaro, Avena, vermouth, and vanilla syrup with ice.
- Strain into an old fashioned glass filled with ice.
- Garnish with a grapefruit peel.
About the Caustic Negroni
This sour cocktail features Scotch whisky as its base. The drink uses amaro and sweet vermouth to give it a bitter and sweet flavor.