CLAKIKICATIOX IN liEEIi AND WINK. 185 



with in the ?/Jrt^>y' ruite and jitii-i inoducts of f?uorar works with- 

 out any recognisable cause, iiml wliich is reganii-d \)\ sumo 

 tochnicists as a purely cheniical process of decomposition, some 

 information will he found in a communication by O. Laxa (I.). 



The fact, of which mention has already l)een made, that 

 certiiin albuminoid constituents are extractexl from yeast cells 

 by ethyl ether, has V)een utilised in pnictiee by H. Hlchneh 

 and M. (luruKK (I.), who manufacture nutrient preparations 

 therefrom by a patented process. 



j 256.— "Break" and Clarification in Beer and Wine. 



In the formation of head on fermenting liquids tlie aforesaid 

 mucinous excretions from the yeast cell are ass(X"iated to a 

 »rreater or smaller extent, aceordin-,' to circumst;inces, with other 

 mucinous bodies already initially present in the nutrient sub- 

 sti"atum. Their dependence on such assistiince is diminished by 

 the inception of tlie phenomenon known as *' break " in brewing 

 and wineinaking. 



In proportion as the liV)eration of carbon dioxide gradually 

 decreases towanls the end of fermentation, there ensues a 

 diminution of the force by means of which the yeast cells float- 

 ing in the fermenting liquid have so far been kept in motion. 

 Consecjuently the atti-action of gi-avitiition can now make its 

 influence on the cells, which have a higher specific gnivity 

 than the young V)eer or new wine. The resulting sulisidence of 

 the cells is, however, opposed by two forces, namely, the vis- 

 co.sity of the li(juid and the friction l)etween the licpiid and the 

 individual cells. These forces suffer diminution when .sevenil 

 cells adhere to form a small ball, since, whilst the weight of 

 this agglomemtion is e(pial to the sum of the weights of the 

 individual component cells, the surface is c(»nsidei-ibly smaller 

 than the total superficial area of the component parts. Hence, 

 while the downward pressure of the weight remains the sjime 

 jvs before, the surface of contact with the litpiid, and therefore 

 the amount of resisttvnce, is les.s. Now the afores:iid gummy 

 and all)uininous mucinous matters favour, and indeed are in- 

 dispensjible to, this agglomemtion of the cells. When they 

 have accomjilished this task and united the cells into colonies 

 that are visible t<j the una.ssisted eye, the condition known to 

 the brewer as " break " is attained. This condition, which 

 gradually arises ttiwards the entl of primary fermentiition, 

 fiMins. in conjunction with the gi-avitv of the wort, the most 

 inqiortxUit factor for determining tlu- ripeness of young beer, 

 and on this account is carefully observed by the brewer. When 

 the process has gone so far that the initially cloudy wort shows 

 up clear in the sjimpling-glass, with the ye^ist collected together 



