The danger of burning the whisky by introducing the beer directly into the still was so great that the early distillers, especially in Kentucky, conceived the idea of separating the first alcohol distilled from the grain by means of a current of steam. The very simplest possible apparatus was used for this purpose, namely, the splitting of a good straight log, the smoothing of the flat surfaces so they could be brought together again when necessary, the hollowing out of the interior of it so as to make a cylindrical center, the bringing of the two halves together and holding them with iron hoops. The mash was poured into the interior of this hollow log and a current of steam was blown into the bottom of it which gradually took the alcohol out without any danger of burning the grains which remained. This process rapidly gained in favor and has now become practically universal among the whisky distillers of the United States. The resulting product was placed back in the copper still and doubled in the usual way, thus securing the advantage of that form of distillation for the final product.