Now I can confirm my earlier comments about the use of sherry casks for aging Scotch whisky. The citation is David Daiches, SCOTCH WHISKY: ITS PAST AND PRESENT (Glasgow, William Collins Sons & Co., Ltd, fifth impression, 1983). On pages 30 and 31, he describes the long tradition of aging whisky in oak casks that were previously used for sherry. He also notes that sherry casks have been in short supply. Sherry is preferred for the color and mellowness it imparts. Raw wood casks impart a woody flavor that is to be avoided. On pages 131 and 132, he confirms Brian McHenry's point that American oak is preferred. American casks were used for storing sherry in Spain and then used for aging whisky. Because of the short supply of sherry casks, American bourbon whisky casks have been knocked down and shipped to Scotland, where they are rebuilt with larger ends. This may not be the last word on casks, but it comes from someone who knows a lot more about casks and Scotch whisky than I do.