This section is from the book "The Manufacture Of Liquors, Wines, And Cordials, Without The Aid Of Distillation", by Pierre Lacour. Also available from Amazon: Manufacture of Liquors, Wines, and Cordials, Without the Aid of Distillation.
These liquors, when tested in the usual manner, will present a fine color, a good bead, and an excellent body. The first step in this process is to provide one or more filters. These are to be used in giving a body and bead to the spirit. A whiskey barrel will answer. It should be provided with a perforated false bottom, firmly secured about twelve inches above the bottom of the barrel, and it should be, packed in the same manner as the stands or filters (for which, see under its appropriate head),
The first layer should be of sand three inches in depth, and the second composed of rice flour and oatmeal in equal proportions, with a small portion of rice mixed throughout the mass to allow a free passage to the liquid, which should be filtered with rapidity. Some operators use rice flour, with one third of wheat flour, and pack the barrel alternately with this mixture and straw. The straw prevents the agglutination of the mass. In no instance should the mass exceed twelve inches in depth. The barrel should be so adjusted with a faucet fixed in the bottom that barrels could be filled; that is, the liquid should pass from the discharging barrel through the filtering barrel to a barrel ready for its reception at the faucet of the filtering barrel. Spirit filtered in this manner may appear at times heavy in color. This will be removed by allowing it to rest for a few days; if it is required for immediate use, apply finings. The operator will recollect to renew the charges of meal or flour when they should become exhausted, or the sand when it becomes too highly charged with foreign matter, by washing it in clean water. Burnt sugar and tincture of red sanders are the only colors necessary. For their preparation, the reader is referred to the chapter on coloring. The pellitory and Guinea pepper will furnish the artificial strength necessary. For their properties and preparations, see chapter on "Pellitory and Pepper."