4i8 



NATURE 



\Sept. 19, 187-; 



PASTEUR'S NEW PROCESS FOR THE 

 MANUFACTURE OF BEER* 



DURING the last few^ years several improvements 

 have been introduced into the manufacture of 

 beer ; in Germany especially, land of sauer-kraut and 

 hops, much attention has been devoted to this spicy 

 and delicate question. In general, however, the appa- 

 ratus for this manufacture leaves much to desire, and to 

 this day brewers are far from being in possession of a 

 process anything like perfect. Scientific men have given 

 scarcely any attention to the question, which, perhaps, 

 they consider unworthy of their study ; while, like the 

 rest of mortals, overcome by the heat and burden of 

 the day, they perhaps have not disdained at times to 

 raise to their lips the golden beverage, which even the 

 most dainty prefer to the ancient and divine nectar. 



Happily, we have commenced to review our past 

 errors ; the great masters of science have consented to 

 descend from the ethereal heights of their empire, and to 

 bring to bear upon industiial art their precious co-opera- 

 tion. For my part, I prefer a result to a formula, an 

 application to a cloudy theory. Should some, losing 

 themselves in impenetrable mists, turn away their atten- 

 tion with alarm from the useful pursuits of these men of 

 science who approach with satisfaction the vulgar neces- 

 sities of this world, let them do so, so long as M. Liebig 

 is willing to be the world's cook, and M. Pasteur its 

 brewer ! It is an established fact in the eyes of earnest 

 men, that " science," as Flourens said, "ought not merely 

 to remain a source of self satisfaction to the soul who has 

 acquired it, and been elevated by it above the crowd, and 

 that it becomes false as soon as it ceases to be pro- 

 fitable to that crowd." Dunoyer said with justice that 

 " he who is a man of science, and nothing more, knows 

 only how to m.ike science useless to himself." 



M. Pasteur is one of those men essentially scientific 

 and kecnsighted, uho understand the saying Geoffroy 

 St. Hilaire one day made to re-echo through the Insti- 

 tute, " The social question is the first with which to 

 occupy ourselves at the present day." But it was in that 

 same room that Bert exclaimed, " Let us continue to study 

 Nature in her m.ost secret processes, to discover, to 

 measure, to calculate the forces that she brings into 

 action, having no thought of any useful applications we 

 can put our studies to." Without doubt, with his friend 

 Gay-Lussac, the great mathematician would reproach 

 Pellegrini-Savigny with having degraded Science in 

 occupying himself with questions as to alimentation. 

 But on the other side we have the names of Berthollet, 

 Monge, Chaptal, Contc, d'Alembert, Franklin, Geoffroy 

 St. Hilaire, Arago, and especially Pasteur, for whom 

 posterity will undoubtedly have a profound respect. M. 

 Pasteur has added to his other fruitful inventions a new 

 process for improving the manufacture of beer, for which 

 he asked a patent in June 1871 in the following terms : — 



" I desire to take out a patent for five years for a new 

 mode of manufacturing beer, which consists essentially 

 in fermentation sheltered from all contacc with air. 



" The wort, after being boiled, is turned into vessels of 

 wood or iron, cooled in a current of carbonic acid gas ; 

 and then put to ferment. 



" This process is founded upon new scientific data 

 which I have expounded elsewhere, and from which it 

 follows that contact with air is most injurious to the manu- 

 facture of beer. It is applicable to mild and strong, 

 brown or pale ales. 



" 1 wish the beers made by my process to bear in France 

 the name of Bia-es d,- hi Re'cUiiuhe Na/ioiiaL-—l shall say 

 why elsewhere— and abroad that of Biars /ra>i<;a!scs. 



" The disuse of cooling liacs. 



"No loss by evaporation, &c. 



" The abolition of store cellars, for future use. 



* Translated from .in .irticlc by M. A. Jouglet, in the Monitciir'^Siitiilt- 

 fique for September iS/a. 



" An increase of the quantity produced, and, at the 

 same time, an increase in the strength of the beer. 



" The development of a very agreeable ' bouquet.' 



" No further use for ice-houses, for fermentation at a 

 low temperature. 



" .Such are some of the principal advantages to be de- 

 rived from the application of my process, and some of 

 the qualities that will mark the beers de la Revanche." 



On Nov. 4, 1871, an additional certificate, accompanied 

 by the sketch here reproduced, was deposited at the Pre- 

 fecture of the Department of the Seine. 



" The annexed sketch," says 'Si. Pasteur in this addi- 

 tion, " represents the construction of the apparatus for the 

 application of the new process of beer manufacture. A 

 description of the design accompanies i'. 



" The size of this apparatus varies with the importance 

 of the manufacture. It can be made of any size, from 

 one hectolitre to 100,000 hectolitres. When the appara- 

 tus is of a somewhat considerable size, the employment 

 of carbonic gas is indispensable to prevent the formation 

 of deleterious ferments — l.ictic ferment, butyric ferment, 

 injurious alcoholic ferment, &c. The employment of .lir, 

 previously purified by calcination, by pissing it through 

 cotton, or by any other mode, is also a remedy for this 

 drawback. A very small quantity of air is not injurious, 

 perhaps even ultimately improves the quality of the beer. 

 The beer can absorb all the flavour which malt and hops 

 can give it ; it can acquire a thoroughly free t.iste, spark- 

 ling limpidity, great strength, and in general all its cha- 

 racteristic qualities, only if we can totally, or in a very 

 large measure, suppress the combustion which takes place 

 in the ordinary process. 



" We can also fill up the void which is made in the 

 apparatus during the cooling of the wort, by bringing the 

 apparatus into connection with a vessel full of warm 

 wort, to kill the seeds of disease in the wort and in ihe 

 beer which is the ultimate result. 



"A man-hole is necessary at those parts of the appa- 

 ratus marked F, F, when they are of great size. 



" The cylinders should be surrounded with a mufH.r of 

 flannel." 



On November 25, 1871, M. Pasteur added a new im- 

 provement to his invention. 



" The facility with which my apparatus may be applied 

 will be increased by the employment of carbonic acid gas, 

 after a more convenient fashion. 



'■The carbonic gas produced during fermentation, after 

 having passed through a washing-flask, to be freed from 

 any froth it might hoIJ, is delivered into a zinc or tin re- 

 servoir, placed a little below the fermenting ap.ar.iiu-s. 

 At the lower part of this reservoir are arranged a number 

 of sockets or ta^s. When it is desired to cool the wort in 

 presence of the carbonic acid, as it is useless to mix up 

 this g.is with the liquid, it is sufficient to put one of the 

 taps of the reservoir in communication with one of the 

 tubes of the apparatus F, F, F'. This arrangement enables 

 us to do without a gasometer, and obviates all the difficul- 

 ties that could result from the movement of a gis which 

 ought to overcome the resistance of liquid. Moreover, 

 as the reservoir always keeps itself lull, its capacity 

 need not be very large. 



" With a rapid cooling we can dispense with the 

 use of carbonic acid ; we can even allow ordinary air 

 to enter in proportion as the bulk of the wort di- 

 minishtd while cooling." 



The germs of disease in the wort are killed in the 

 boiling wort, and those which the volume of free air 

 just mentioned may carry, will not have time to de- 

 velop in the wort, if the cooling process has been 

 prompt — a condition always easy to bring about by 

 having a suitable flow of water, and by having the 

 bulk of wort always comparatively small. 



" In reference to these assertions, it may not be useless 

 to recall the proof I formerly gave of the remarkable fact, 



