1 Jury, 1898.] QUEENSLAND AGRICULTURAL JOURNAL, 59 
Viticulture. 
MALADIES OF WINE. 
THEIR CAUSE AND TREATMENT. 
By E, H. RAINFORD. 
In describing the diseases to which wine is subject, it is necéssary to use, in 
some cases, French significations to distinguish them, as the English terms—acid, 
sour, turned, scuddy, &¢.—indicate a condition of the wine, and not the malady 
with which it is affected. Several wines may be sour and turned, and each be 
affected with a different disease and requiring a different treatment. The 
principal defects which affect wine are Casse, Acesence, Tourne, Pousse, 
Graisse, Amer; all but the first are due to the action of a special organism or 
ferment. 
THE ‘CASSE.” 
The malady known as “casse’’ is caused by an imperfect balance of the 
constituents of the must, due to either abnormal vegetation during the ripening 
of the grape or to the effects of cryptogamic diseases of the vine. In the 
latter case, cells of the fruit and leaf have been destroyed by the growth of the 
fungus, and, as a consequence, the functions of the plant interfered with in 
the formation of the fruit constituents, a similar effect being produced by 
abnormal vegetation during the ripening period, caused by either cold or 
continued wet weather, &c. 2 
The signs by which “ casse’’ may be known are the browning or blackening 
of both red and white wine on exposure to the air, followed by turbidity and 
deposition of a sediment containing more or less of the colouring matter. In 
the cask or bottle the wine will appear to be perfectly sound, bright, and of 
good colour, but if some is poured into a tumbler, or a bottle of the wine is 
left uncorked, after some minutes or hours, according as the wine is more or 
less affected, a discolouration begins at the surface, having the appearance of 
an iridiseent film which gradually passes down to the bottom of the wine and is 
deposited in the form of a sediment, leaving the wine clear again, but with the 
colour materially affected, red wine becoming brown or even yellow, and white 
wine yellow or leaden. At the same time the wine becomes flat, and occasion- 
ally acquires a disagreeable taste. . 
Formerly the causes of the above phenomena were not understood; 
but later researches have tended to prove that the discolouration is due to 
the action of an oxidising diastase called oxydase, existing in abnormal 
quantity in the wine. ‘This substance, produced in the grape, has the power 
of fixing the oxygen derived from the atmosphere upon the most oxidisable of 
of the glucosides, which in this case is the colouring matter. From the causes 
before mentioned the colouring matter is in an unstable condition, and there is 
an abnormal development in the grape of oxydase which acts, so to say, as 
-earrier of the oxygen to the colouring matter, which becomes either insoluble, 
and is deposited as a sediment, or the oxidisation causes a darkening in the 
case of white wines. Some writers are of opinion that ferrous salts in 
solution in the wine play a réle in precipitating the colour, but do not explain 
why “ easse’” is more prevalent after unfavourable seasons or in wine made from 
diseased grapes. 
