Of Four Roses' ten recipes, OESF is arguably the most distinctive. The O tells you it's distilled at the Lawrenceburg distillery (all Four Roses is); the E denotes the lower-rye mashbill (75% corn, 20% rye, 5% malted barley); the S is a constant — straight whiskey; and the F indicates the herbal yeast strain, which throws unusual mint, dill and anise aromas that no other bourbon producer cultivates.
The lower-rye E mashbill lets the F yeast speak clearly. Where high-rye recipes can bury the yeast character under pepper and spice, E gives you a sweet, corn-forward canvas on which the herbal notes paint freely. At barrel strength from a single cask, the effect is vivid: OESF smells unlike anything else on the bourbon shelf.
Four Roses introduced the full ten-recipe matrix under Jim Rutledge's stewardship after Seagram's ownership ended in 2002, when the brand returned to the US market after decades of being exported almost exclusively to Japan and Europe. The single-barrel barrel-strength programme, where retailers and groups select individual casks, has turned OESF into something of a cult pick — the recipe connoisseurs hunt for when they want Four Roses at its most idiosyncratic.
Add water cautiously. A few drops amplify the herbal character; too much and the orchard fruit takes over. Either way, this is bourbon for drinkers who think they've seen everything Kentucky has to offer.
