ON THE PRESENCE OF FUSEL OIL IN BEER. 

 By William M. Hamlet, F.C.S., Government Analyst. 



[Read before the Royal Society of N.S.W., November 2, 1887.2 



The beverages we know so well as fermented malt liquors are so 

 complex in their composition and so liable to change and decay, 

 that until the last few years very little was known of their exact 

 nature and internal constitution, still everyone was supposed to 

 know all alono- the difference between o-ood and bad beer. From 

 the time of Falstaff to the present clay, the beer drinker has always 

 been a trifle suspicious of his brewer, and ever ready to exclaim 

 with that fat and valiant judge of good liquor — vt You rogue, 

 here's lime in this sack," and he generally experiences a most lively 

 satisfaction in changing his " barley bree." 



It would help us to clearer views on this subject if we consider 

 what beer really is, or rather what it ought to be, ai\d what are 

 the chemical and biological processes involved in its manufacture. 

 I may therefore at once define beer as an alcoholic beverage made 

 from malt, hops, yeast and water. 



As briefly as I can describe it, the process of brewing ordinary 

 beer is as follows : — Malt is crushed between rollers and dissolved 

 in, or extracted by water at a temperature which is more or less 

 a secret with the individual brewer — generally from about 140 or 

 145 D to 150° Fah., by this means an infusion of malt is made, the 

 operation being known as that of mashing : the vessel in which it 

 is produced being termed the mash tun, while the product is known 

 as the wort. The water found most suitable for mashing is one 

 containing very little or no organic matter and a somewhat large 

 proportion of sulphate of lime, which makes what is called a I 'tar d 

 water; for porter brewing, however a softer water is used. By 

 using a hard water certain albuminous matters contained in the 

 malt are prevented from coming into solution ; that is, the 

 albumenoids are rendered much less soluble. 



The chief object of the brewer in mashing is to convert the 

 starch present in the malt into a peculiar variety of sugar termed 

 maltose : this change being effected by the presence of a body 

 known as diastase. A very small amount of this diastase is 

 sufficient to convert an unfermentable body like starch into maltose. 

 One part will transform 10,000 parts of starch into maltose — a 

 sugar which is directly fermentable. 



P— November 2, 1887. 



