CHAP. XVI.Of the Distillation of Malt Spirits.
TheWash, or Liquor being prepared by Brewing and Fermentation, as directed in the first and second Chapters of this Treatise, the Still is to be charged with it, and worked off with a pretty brisk Fire. But it should be observed, that the only Apparatus used in this Process, is the Alembic with a Refrigeratory, as represented inFig. 1.
The Wash being of a mucilaginous Nature, a particular Management is necessary to prevent its burning, and cause it to work kindly in the Still: If it should happen to be burnt in the Operation, the Spirit will have a most disagreeable Flavour, which can hardly ever be removed; and therefore to prevent this ill Effect, the Wash should be made dilute or thin, the Fire well regulated, and the whole kept in a continual Agitation during the whole Process. The most judicious Distillers always take care to have their Wash sufficiently diluted, and constantly find their Spirit the purer for it. With regard to the Fire, it may be easily kept regular by a constant Attendance, and observing never to stir it hastily, or throw on fresh Fuel; and the stirring of the Liquor in the Still is to be effected by Means of a Paddle, or Bar kept in the Liquor till it just begins to boil, which is the Time for luting on the Head; and after which there is no great Danger, but from the improper Management of the Fire: This is the common Way; but it is no easy Matter to hit the exact Time, and the doing it either too late, or too soon, is attended with great Inconvenience, so that several have discovered other Methods; some put more solid Bodies into the the Still with the Wash; others place some proper Matter at the Bottom and Sides of the Still, which are the Places where the Fire acts with the greatest Force.
The Use of the Paddle would, however, answer better than either of these Methods, could it be continued during the whole Time the Still is working; and this may be done by the following Method: Let a short Tube of Iron or Copper be soldered in the Center of the Still-head, and let a cross Bar be placed below in the same Head, with a Hole in the Middle, corresponding to thatat the Top; through both these let an iron Pipe be carried down in the Still, and let an iron Rod be passed through this with wooden Sweeps at its End; this Rod may be continually worked by a Winch at the Still-head, and the Sweeps will continually keep the Bottom and Sides scraped clean, the Interstices of the Tube being all the time well crammed with Tow to prevent any Evaporation of the Spirit.
The same Effect may, in a great Measure, be produced by a less laborious Method, namely, by placing a Parcel of cylindrical Sticks lengthways, so as to cover the whole Bottom of the Still, or by throwing in a loose Parcel of Faggot Sticks at a Venture; for the Action of the Fire below moving the Liquor, at the same time gives Motion to the Sticks, making them act continually like a Parcel of Stirrers upon the Bottom and Sides of the Still, which might, if necessary, be furnished with Buttons and Loops, to prevent them from starting. Some also use a Parcel of fine Hay laid upon the loose Sticks, and secured down by two cross Poles, laid from Side to Side, and in the same Manner fastened down with Loops. Care is to be taken in this Case not to press the Hay against the Sides of the Still; for that would scorch nearly as soon as the Wash itself; but the Sticks never will: These are simplebut effectual Contrivances, and in point of Elegance, they may be improved at Pleasure.
There is another Inconvenience attending the distilling of Malt Spirit, which is, when all the Bottoms, or gross mealy Fœculence is put into the Still along with the Liquor, the thinner Part of the Wash going off in Form of Spirit; the mealy Mass grows by Degrees more and more stiff, so as to scorch towards the latter Part of the Operation. The best Method of remedying this is to have a Pipe with a Stop-cock, leading from the upper Part of the Worm-tub into the Still; so that upon a half, or a quarter Turn, it may continually supply a little Stream of hot Water, in the same Proportion as the Spirit runs off, by which Means the Danger of scorching is avoided, and the Operation, at the same time, not in the least retarded.
InHolland, the Malt Distillers work all their Wash thick, with the whole Body of Meal among it; yet they are so careful in keeping their Stills clean, and so regular and nice in the Management of their Fires, that though they use no Artifice at all on this Head, only to charge the Still while it is hot and moist, they very rarely have the Misfortune to scorch, except now and thenin the Depth of Winter. When such an Accident has once happened in a Still, they are extremely careful to scrape, scrub and scour off the Remains of the burnt Matter, otherwise they find the same Accident very liable to happen again in the same Place. But beyond all the other Methods in Use on this Occasion, would be the working the Stills not by a dry Heat, but in aBalneum Mariæ, which might possibly be so contrived by the Bason being large, and capable of working a great many stills at once, as to be extremely worth the Proprietor’s while in all respects.
Another Requisite to be observed is, that the Water in the Worm-tub be kept cool; this may be affected, by placing in the middle of the Tub a wooden Pipe or Gutter, about three Inches square within, reaching from the Top almost to the Bottom; by this Contrivance cold Water may, as often as necessary, be conveyed to the Bottom of the Worm-tub, and the hot Water at the Top forced either over the Sides of the Tub, or, which is better, through a leaden Pipe of moderate Size, called a Waste-pipe, soldered into the Top of the Tub, and extended to the Gutter formed to carry away the Water.