After blending DEWAR’S 12 Blended Scotch Whisky, it is returned to vintage oak casks so it can mature a little more. This extra step is called double barrel aging and it makes DEWAR’S 12 Blended Scotch Whisky an even smoother blend with a long, lingering finish. DEWAR’S® 12 Blended Scotch Whisky is warm, buttery and mellow.