Four Roses OESO Single Barrel is a premium Kentucky straight bourbon whiskey, offered in a 750mL bottle and available in limited quantities at Costco (limit 1 per member). Each bottle is drawn from a single barrel, making every release a distinct expression unique to that individual cask.

OESO is one of Four Roses Distillery's ten distinctive bourbon recipes, combining the E mash bill — composed of 75% corn, 20% rye, and 5% malted barley — with the O yeast strain, which contributes rich fruit characteristics of fresh berries and cherries. The spirit is bottled at 100 proof and aged approximately seven to nine years before release.

On the nose, the bourbon presents ripe red fruit, honey, and mellow oak. The palate delivers flavors of ripe cherry and vanilla, while the finish is soft and long-lasting. OESO is consistently regarded as one of the most coveted recipes in Four Roses' single barrel program, prized by collectors and bourbon enthusiasts alike for its balance of corn sweetness and expressive fruit character.