This section is from the book "Alcohol, Its Production, Properties, Chemistry, And Industrial Applications", by Charles Simmonds. Also available from Amazon: Alcohol: Its Production, Properties, Chemistry, And Industrial Applications.
(Egrot and Grange, Paris).
In France, the juice of beets for alcohol-making is obtained in a manner quite similar to that adopted in the sugar factory for extracting the juice to be used as a source of sugar. After being washed and sliced, the beets are extracted with water by a process of diffusion, which takes place in a battery of vessels set in series. These vessels, charged with the slices of beet, are so arranged that the water issuing from the bottom of one vessel passes into the top of the next, percolates downwards through the packing of beet slices, and extracts their sugar as it goes. The same thing occurs in the next vessel, and thus by the time the end vessel of the series is reached, the juice has become sufficiently rich in sugar to be ready for fermentation. To minimise the action of harmful bacteria during fermentation, the juice is slightly acidified with sulphuric acid, and frequently small quantities of antiseptics such as fluorides are added.
In Austria-Hungary, also, sugar-beets have in recent years been extensively used as a source of alcohol.1 Many of the distilleries use the diffusion process described above; but others utilise the plant formerly employed for mashing potatoes, and extract the beets by heating with steam under pressure in a conical ("Hentze") converter. The beets are freed from leaves and then topped, the roots and tops being stored separately and the tops worked off first, as they are more prone to lose sugar during storage. For the steaming operation a pressure of two atmospheres, maintained for one and a quarter to one and a half hours, is sufficient, all the sugar being then dissolved, and the beet tissues reduced to a pulp. Both potatoes and beets are sometimes steamed together, the lower half of the converter being filled with potatoes and the upper half with beets. When the steaming of the potatoes is completed, they are blown out into the fermenting vessel. The beets require longer treatment, and are given another half-hour's steaming before the pulped mass is in its turn blown out to be fermented. Economically, the use of beets is said to compare favourably with that of potatoes.