What type of bitters is used in the Oaxacan Old Fashioned?

The Oaxacan Old Fashioned is a cocktail that typically features the unique flavor combination of mezcal and bitters. In this case, the correct answer points to the use of grapefruit bitters, which complement the smoky notes of mezcal and elevate the drink with a citrusy brightness. Grapefruit bitters add a refreshing and aromatic quality that balances the richness of the mezcal and the sweetness from any added syrup, offering depth to the cocktail.

Using grapefruit bitters aligns well with the themes found in the Oaxacan Old Fashioned, as they enhance the overall flavor profile without overpowering the other ingredients. The careful selection of bitters is crucial in cocktail crafting, especially in a drink that celebrates the distinct flavors of its base spirit.