One of the initial releases in Four Roses' new Single Barrel Collection, OBSF is a component of Four Roses Small Batch Select.  Featuring the higher rye "B" mash bill (60% corn, 35% rye, and 5% malted barley) and "F" yeast strain (described by four roses as bringing herbal notes), these single barrels are bottled at 100 proof.  Though not age stated, they are likely in the same 7-9 year range as the standard single barrel bottlings.  Tasting notes from the distiller include delicate rye, apple, mint, clove, and cocoa.