484 
Derrects anp DISEASES oF WINE. 
Wine, like milk, is susceptible of attack and deterioration from 
a number of causes. It may be defective or it may be diseased, or, 
as it often happens, it is both defective and diseased at the same 
time. The defects are either natural or acquired. 
Natural defects are those inherent to the commoner and inferior 
kinds of grapes; to the soil itself, the manures used, to insufficient 
ripeness, or to the bad manipulation during the process of making. 
Acquired defects or diseases result from carelessness and tainted 
casks and vessels. These defects only manifest themselves after 
fermentation. They constitute the diseases of wines as is generally 
understood, and each individual one is produced by the presence 
and the work within the wine of numberless microbes, each kind 
easily identified from the other by its shape and other characteristics 
which accompany its growth. 
I will rapidly review the more common defects and diseases 
met with in wines. 
Earthy taste——Often inherent to the soil where the grapes were 
grown. Clayey soils are in this respect more susceptible of impart- 
ing an earthy taste to wines than do light loams, which produce 
wines said to be “clean” to the taste. This defect can be aggravated 
by long fermentation, especially when the stalks have not been suffi- 
ciently separated. Long intervals between rackings also add to it, 
and for that reason it is advisable to draw the clear wine from over 
its lees more frequently than would otherwise be done. Occasional 
light fixings after racking, followed up by another racking, will be 
found helpful. 
Greenness.—This defect is caused by an undue proportion of 
tartarie acid and malice acid in wet seasons, when the grapes have 
not matured properly. A strong attack of a fungoid disease, 
bringing about a loss of the leaves of vines, will favour the same 
defect. Blending in the vat with a proportion of dead ripe and 
healthy grapes is the best means of correcting this defect. 
Harshness, caused by excess of tannin. This constituent of 
wine, which is essential to its good keeping, is generally more per- 
ceptible in young wines. Time mellows it down, and it is gradually 
transformed into gallic acid. Beware of iron coming into contact 
with such wine, as the chemical reaction which follows would pro- 
duce ink. If the harshness is excessive, heavy finings by means of 
gelatine, 3 to 3% ounces per 100 gallons, will precipitate and remove 
a portion of the tannin. As such a fining would also remove some 
of the colouring matter, wines already light in colour should be 
treated in some other way; for such wine, blending with light, 
mellow wines, low in tannin, will correct the defect. 
