GKIIMINATION OF SACCHAHOMVCKThX 143 



WHS exteiuled to tlit* attempts niiide, by gentle Wiinuiug, to 

 weukeij or kill tin* g«*niis in other lic|ui<ls, e.ij. milk (§ 128), 

 wlnMviii thest' rlieinical auxiliaiit'S an* lacking'. This iiu|K(rt.-int 

 (litVereuce has liot l)i'eii sulfiL-ieiitly ajipn-cialeil in the liti'ruture, 

 and is not infreciuently ignorwl in pnictife, the consequence 

 being failures and illusory results. So fiu* ati concerns the 

 pasteuri.sation of wine, beer, an<l must, which is all that we have 

 to consider in tiiis place, the techiiolu'^y of the pnx-es.s (which 

 is pi-actise«l in a variety of ni(>ditic4itionK), must be dismissed in 

 a few weirds, the reader being referred, for further infijrinatioit, 

 to the desciiptions given by Pasteiii (XIV.), li.vuo and Macu 

 (I.), and F. Malvezi.v (I.). The forms of apjuinitus latterly 

 constructetl for the jNisteurissition of wine have been describe<i 

 by Yassii.mkhe, Chaiivet and U. CJAVttN (1.), the last name<l of 

 whom (I.) has also made compamtive examinations of several 

 systems. Illustrations and descriptions of the apparatus 

 de.signed for pasteurising (or jvs it is often erroneously .styled, 

 sterili.sing) l>ottled Ijeer, will be found in Fas.sbender's "Techno- 

 logie," and in the handbooks mentioned in !i Si. 



The dithculties encountered in the practical pa.steurisation 

 of wine, beer and must are mainly of three kinds. Fir.^t is the 

 selection of the lowest temperature at which it is jK)s.«.ible to 

 attuin the end in view, viz. to kill the yejist and Ivicteria, or 

 remler them incajxible of setting up any fuiiher action in the 

 liquid in question. This teniperatuie, however, necessjirilv 

 varies acconling to the species of the organisms present, and the 

 chemical composition of the wine or l»eor. Hence no invariably 

 applicable figure cjin be given, though 50° to 60" C may usually 

 l>e adhered to. The fuilher this limit is exceeded in the 

 direction of the boiling iK)int, the more decitled will be the 

 boiletl — or in the ca.se of l>eer, the so-cnlletl l»reiMl-like — flavour 

 of the liquid treated. This flavour larijelv owes its ori<'in t<> 

 the mcMlitic.ition of certjiin constituent,s of the hot licpiid by 

 oxygen. To afford a remeily — and this forms the second 

 difliculty — not only must the acce.ss of air l)e prevented, i.e. by 

 warming the liquid in corked lK)ttles or bunged ca.sk.s, but also 

 the oxygen jtre.sent in solution hius to be eliminate*! — as was 

 propo.sed in H. Gi-onwald's (Jennan Patent, No. 98,584 (1896). 

 The third ditKculty, which we need not now consider, resides 

 in the formation of a coagulum protluced by the heat, and con- 

 stituting a deposit which, .since it would spoil the appejinince of 

 the wine when poured out, has eventually to be removetl by 

 liltnition, followed by a .second ]>a.steuri.sation. 



Some very tenacious bacteria are able to survive the jwsteur- 

 isi\tion of the three liquids mentioned, but are saircely cni«ible 

 of doing any subsiNpient damage. Thus, in a sjimple of Munich 

 beer sufliciently pasteurised for the exjxjrt tnule, IXjUiEXS (I.) 

 found 34 bj\cteria per c.c, all able to develop on nutrient 



