This section is from the book "The Steward's Handbook And Guide To Party Catering", by Jessup Whitehead. Also available from Amazon: Larousse Gastronomique.
We are told by the French authorities, and we have no reason to doubt the veracity of their statements, that nearly one-half of the brandy imported into Her Imperial Majesty's British domains is nothing more or less than pocato spirit - one of the very worst and fiery of spirits, heretofore supposed only to be used by absinthe-makers of the most unprincipled type. The modus operandi of its preparation for the British market is somewhat similar to the treatment employed in the making of sawdust brandy from the sawpit refuse, and the dust of pine and fir trees. The potato undergoes treatment with sulphuric acid and water to develop or change the dextrin into grape sugar This, after many hours' boiling, is mixed with a certain proportion of lime, which causes a precipitate, and destroys or changes the sulphuric acid taste and qualities. It is then fermented with sound malt leaven for about three days, when it is distilled, giving an abundant yield of pure spirit of the strongest and most virulent type.