42 QUEENSLAND AGRICULTURAL JOURNAL. [1 Jan., 1899. 
unclean plant is twofold. First, the wooden material saturated last season 
with must may have become mouldy, which would communicate disagreeable 
tastes to the wine; second, dirty plant may be swarming with germs of bacteria 
or their spores, which would not fail to multiply in the must, and thereby 
affect its soundness and quality. Where vats and casks have a decidedly bad 
smell, the reader is referred to last month’s article in this Journal for their 
treatment. When they have only the usual smell of dry cask, they should be 
washed out and scrubbed with a bucket or two of water acidified with sulphuric 
acid. A vat-full can be prepared beforehand in the proportion of 2 Ib. of acid 
to 100 gallons of water. Wash all the plant down with this solution; it is too 
weak in acid to affect the ironwork, but is a splendid germ-destroyer and 
sweetener or tainted wood. If the vigneron cannot or will not use the acidified 
water, he can wash the plant with a 5 per cent. solution of bisulphite of lime 
(obtainable at breweries). If a large fermenting vat has become mouldy and 
green inside, as will happen if kept in a damp place, it is well to burn the 
interior surface with a plumber’s lamp, and then well scrub down with salt 
water, sulphuric acid solution, or bisulphite solution. 
Cleanliness of surroundings should also be attended to, keeping the cellar 
clean and sweet by occasionally whitewashing the walls and sweeping up all 
refuse—bruised grapes, husks, &c., lying about, breed countless germs. 
ACIDITY OF MUST. 
Mention was made in the article for this Journal for February, 1898, that 
for the germs of vinous fermentation to do their work efficiently the con- 
stituent parts of the must should be in equilibrium, and when the proportion 
of tartaric acid falls too low, the Saccharomyces lose some of their vitality, 
while that of the noxious germs is increased. In addition to the effect upon 
fermentation, the wine will be flat to the taste, imperfect in colour, and wanting 
in bouquet, and, moreover, it will always be susceptible of change and deteriora- 
_ tion. Wine made from must with sufficient acidity will be of a lively colour, 
fruity, and with a pleasant bouquet, besides keeping much better. 
If grapes are allowed to become too ripe, they lose acidity, and the must 
will be deficient ; on the other hand, if in some places grapes are vintaged too 
early, they will lose in sugar, so that it is preferable to add a little tartaric 
acid to musts of ripe and over-ripe grapes—a practice permitted in all wine- 
making countries. 
Again, in wet seasons the must will be deficient in tartaric acid, and also 
that from grapes affected with cryptogamic diseases (oidium, black spot, &c.) 
Conversely, during very dry seasons, or when grapes have matured with 
a long spell of dry weather and burning sun, the must rarely requires any 
addition of acid. 
The quantity to be added will, of course, depend upon the amount already 
contained in the must, and this ean only be known by testing with a proper 
apparatus. For those who do not possess the apparatus and practical know- 
ledge of testing, the best plan is to send an average sainple of the grapes 
' to be vintaged to this Department a day or two before picking to be tested, 
and the acidity will be made known by return of post. Must from the 
generality of wine grapes requires from 8 to 10 per mille of tartaric acid, and 
that from Jacquez or Lenoir not less than 12 per mille, otherwise a portion of 
the colour will not be fixed, but will deposit in the lees. One per mille may 
be calculated as 1 Ib. per 100 gallons, so that, if a Lenoir must only contains 
10 per mille of acidity, 2 lb. of tartaric acid must be added to each 100 gallons 
of must if all the colour is wanted; if the amount of colour is immaterial, 
the acid need not be added, as 10 per mille is sufficient for the preservation of 
the wine. On the hand, if a Hermitage or Espar must only contains 6 per 
mille of acidity, 2 per mille should be added, as its acidity is too low to ensure 
soundness and quality. 
