PROCE88 DSED IN CALIFORNIA. 11 



stances are e-enerallv regarded as adulterants and injurious, they should 



■ 



not be used. 



(2) Mechanical means are sometimes employed. The germs are 

 either removed by some mechanical means, such as a filtering or a 

 centrifugal apparatus, or they arc destroyed by heat, electricity, etc. 

 ( >f these, heat has so far been the most practical. 



When a liquid is heated to a sufficiently high temperature all organ- 

 isms 'm it arc killed. The degree of heat required, however, differs 

 not only with the particular variety of organisms, hut also with the 

 liquid in which they are held, 'rime i- also a factor. An organism 

 may not he killed if heated to a high temperature and quickly cooled. 

 If. however, the temperature is kept at the same high degree for some 

 time, it will he killed. It must also be borne in mind that fungi, includ- 

 ing yeasts, exist in the growing and the resting states, the latter being 

 much more resistant than the former. A characteristic of the fungi and 

 their spores is their great resistance to heat when dry. In this state 

 they can he heated to 212 F. without being killed. The spores of 

 the common mold are even more resistant. This should he well con- 

 sidered in sterilizing the bottles and corks, which should he steamed 

 to 240 F. for at least fifteen minute-. 



Practical tests so far made indicate that must can he safely sterilized 

 at from 1*;;, to 176 F. At this temperature the flavor is hardly 

 changed, while at a temperature much above 200 F. it is. This is an 

 important point, as the success of an enterprise of this character 

 depends entirely upon the flavor and quality of the product. 



Such a vast difference exists in the methods pursued in California 

 and in the Eastern States that a description of each is here given. 



PROCESS USED IN CALIFORNIA. 



This method, as described in Bulletin No. 130 of the California 

 Experiment Station, is in substance as follows: Only clean and per- 

 fectly sound grapes, preferably those having a high natural acidity, 

 picked and handled when cool, should be used. This fruit should not 

 be too ripe or the must will be too sweet and be difficult to clarify. The 

 grapes are pressed immediately and the juice is run into clean, ster- 

 ilized puncheons or other receptacles. If the must is 59- F. or under, 

 it may be left to settle for twenty-four hours or more. This rids 

 the juice of most of the floating solid matter and facilitates sub- 

 sequent filtering. It is then passed through a continuous pasteurizer 

 (see fig. 1) and heated to 175- F., and should come out not warmer than 

 77° F. when it is run directly by means of a block-tin pipe into fresh 

 vessels. For this purpose sterilized puncheons or other casks may 

 he used, although" casks or vats of metal, lined with enamel, would be 



better. 



The f?reatest care must lie taken to avoid contamination of the must 



