The theory and practice of brewing illustrated ... / by W.L. Tizard.
- Tizard, William Littell
- Date:
- 1857
Licence: Public Domain Mark
Credit: The theory and practice of brewing illustrated ... / by W.L. Tizard. Source: Wellcome Collection.
553/584 page 5
![expectations; but while thus imuienscly augmenting the utility of the Octuple, it also augmented the cost of constructing it; and as some brewers always i)rofer the lowest-priced instruments, Mr. Tizard is |)repared to supply, not only the perfected Oc’i uple, but also tlie Octuple as originally constructed. In the latter shape,—the sliapo, namely, of a wooden barm-back, with a coiled attemperator suspended beneath it,—its cost is about one-half of that of the metallic Octuple ; but the following comparison will show that it is not to the brewei’’s interest to select the lower-])riced instrument, since its inferiority to the metallic Octuple is far too great and too important to be compensated by any dilference in the cost of construction. A few of the more marked advantages of a hollow metallic float, capable of being kept filled with cold water, as compared with a solid wooden one, destitute of that capability, are the following. In the first place, the metallic Octuple a])])lies attcniperation to the surface of the fermenting wort,—the portion of the wort to which alo7ie attemperation oufit to be applied, in order to the proper conduction of the vinous fermentation ; whereas when the coiled attemperator (or .any other that can be suspended from the wooden float) is used, the attemperation is 7iot applied to the surface at all, but is ajjplied instead to a portion of the wort lying some distance below the surface, since the coiled attemperator must necessarily be immersed m the wort, instead of floating on it, as the perfected attemperator, or metallic Octuple, does. The latter has also greatly the advant.age of the former in the superior ease and facility with which it can be cleaned, and also in the fact that it exercises its refrigerating influence, not only upon the surface of the wort beneath it, but also upon the yeast and beer which rise up round its sides, .and fall upon its barm-back, or upper face. The stream of cold water flowing through the metallic Octuple keeps this upper face, or barm-back, ahv.ays cold, and thereby effects sever.al most important, and hitherto unparalleled, beneficial results. Amongst others, it ensures the complete separation of the yeast from its accompanying beer, causing in due course the precii)itation of the ivhole of the yeast, and thus so thoroughly freeing the beer from yeasty admixture, and at the same time cooling it at so low a tempera- ture, as to preclude the possibility of its imparting, w’hen it redescends into the gyle-tun, cither the ycast-bite, or the slightest acid im|)regnation. When the Octuple is constructed of wood, the case is very different. No attemperating influence can then be applied to its u])per surface, or barm-back; and the temperature of the barm-back is therefore entirely beyond the control of the brewer, being dependent, not—owing to wood and fluids being each bad conductors of heat—upon the attemperator suspended beneath it, but partly upon the temperature of the atmosphere, and partly upon that of the overflowing yeasty wort. The consequence is that in summer time the temperature of the barm-b.ack is so high, that tw'o very objectionable results accrue. On the one hand, the beer and yeast of which the Avort Avhich flows on to the barm-back consists, are separated so impeifectly that the beer which returns into the gyle-t>m carries with it many yeasty particles, which are liable to be dissolved by the alcohol of the wort in the gyle-tun, and thus to impart to it a yeast-bitten character, while, on the other, instead of the fermentation of the Avort AA'hich Aoaa’s on to the barm-back being there checked, it is so accelerated that part of its aleohol flies off into the atmosphere as alcoholic ether, Avhile much of the remainder is conA^erted into acetic acid, Avhich, on descend- ing into the gyle-tun, contaminates its Avhole contents. Nor are these the only respects in Avliich the Avooden Octuple is greatly inferior to the metallic one. When the metallic instrument is used, its conic.al bottom provides an inclined plane, up Avhich the globules of carbonic acid gas, AA'hich arc the vehicles by Avhich the yeasty j)articles arc conveyed to the surface of the Avort, can easily AA'ork their Avay to the sides of the Octuple, and thus ensures that the whole of the yeast shall be removed from the Avort, and collected upon the barm- back; but Avith the Avooden Octuple this is not the case. The Avooden instrument may be made more conic.al on its under-side than the inventor .at first constructed it, but it c.annot be made so conic.al as the metallic Octuple, since to m.akc it so Avould render it too cumbrous and uiiAvieldy for use, unless it Avere m.ade in parts, in Avhich case it AVould be liable to constant derangement, and premature destruction ; and it consequently presents, OAving to its necessarily greater flatness, much inferior facilities for the IIoav upAvards of the little globules, or “ balloons,” of gaseous yeast, and is exceedingly apt, especially in hot AA’eather, to press prematurely o\it of them the c.arbonic acid gas Avhich buoys them up, and thus to cause a great part of the yc.ast to collect at the bottom of the gyle-tun, instead of at tlie top of the barm-b.ack, thereby occasioning considerable loss both of yeast and beer, and incrc.asing the danger of the beer becoming yc.ast-bittcn. If to .all this it be .added that Avhen the Avooden Octuple is used, the Avort Avill in many cases require occasional rousing,—which m.ay be effected cither by passing the handle of the rouser through the AVooden float, or through a stuffing-box, fixed in any convenient part of the fermenting vessel,—Avhile the loAV tempera- ture at AA’hich the metallic Octuple cools the Avort on its harm-back adds to its manv other advantages that of obviating this necessity, in all but very extreme cases, since the cold streams of Avort AA’hich return from the barm-b.ack into the gyle-tun, through the tubes passing through the Octuple, acquire by the cooling operation such an incrc.ase of density th.at they at once descend to the bottom of the gyle-tun, thus causing the Avarmcr contents of the A’csscl to .ascend, and go through a similar process in their turn, and thereby keeping the Avort in a proper state of cir-cul.ation, Avithout the aid of any “ r.mscr,” the great superiority of the metallic .apparatus over the Avooden one Avill be suflieicntly apparent. The Avooden Outupi.k in a Avoid, is a useful instrument, but fails far short of'perfection ; the perfected metallic Octuple leaves nothhuj to be desired. ’](https://iiif.wellcomecollection.org/image/b28053412_0553.jp2/full/800%2C/0/default.jpg)
