1 Frs., 1898.] QUEENSLAND AGRICULTURAL JOURNAL. 127 
to enter into here, the germs lose some of their vitality, and perform their 
work more or less imperfectly, for micro-organisms as well as animals and 
plants have need of special surroundings and nourishment to be able to 
develop and multiply; the battle for existence is as imperious a law for 
them as for other living creatures; and if the medium in which they fall is 
unfavourable, other species, more robust and less sensitive to their surround- 
ings, will develop at their expense and interfere with their activity. 
This want of equilibrium should therefore be corrected. A must of 1,100 
degrees density ought to contain not less than ‘8 to 1 per cent. by weight of 
tartaric acid, unless it is intended to be strongly fortified to arrest the fermen- 
tation at an early period—in that case the percentage of acidity is not of 
importance; but for light dry wines like chablis, claret, &c., the amount of 
acidity should be carefully regulated, otherwise the conversion of the sugar 
will not be thoroughly effected, the colour will be unstable, and the wine prone 
to after-fermentation. 
This danger will be avoided by the addition of sufficient tartaric acid to 
bring the acidity up to the proper percentage, or by vintaging the grapes 
before they are fully mature. Unfortunately, not all vignerons possess the 
knowledge and apparatus necessary for an analysis for acidity, but if a sample 
of the grapes, or a small bottle of the must pasteurised by boiling, be sent to 
the Agricultural Department in Brisbane a day or two before the vintage 
takes place an analysis would be made, and the inquirer informed of the 
result. In sending grapes or must for analysis, care must be taken to select 
a few smail bunches or portions of a bunch from different points in the vine- 
yard and of a medium state of ripeness. : 
It is of great importance that the temperature of the must should be 
properly regulated during fermentation, as this has great influence on the 
character of the future wine. The most favourable temperature for the 
ferment germs to work in is between 77 degrees and 95 degrees, but unfor- 
tunately in tropical and semi-tropical climates the atmosphere of the ceilar at 
the time of the vintage frequently passes the latter point, and the fermenting 
mass of must and mare in the yats will rise to 100 degrees and over; when 
this happens the Saccharomyces lose some of their vigour; whilst the noxious 
germs are unaffected by the temperature, and may increase in numbers to a 
dangerous extent. It should be the object of the vigneron to reduce the 
temperature as much as possible by artificial means, even at a small cost, if 
he has at heart the quality of wine he is making. The most perfect way of 
keeping the temperature at any degree you desire is by using refrigerating 
machinery, but this, of course, can only be done in the largest and best- 
equipped cellars; after that the best effect is obtained by the circulation of a 
stream of cold water through the must by means of a metal coil inside the vat, 
taking care that the surface in contact with the must be tinned and that the 
diameter of the coil be not too small, otherwise the reduction of temperature 
will be slight. The water can be sent through the coil by gravitation or by 
pumping as circumstances permit, regulating the flow to do the most work. 
Tn default of either of the above systems, the temperature can be materially 
lowered, and at a relatively small expense, by immersing in the vata tin cooler, 
round, and four times as long as its width, containing a refrigerating mixture 
of pounded ice and salt. This arrangement should be fixed so that it stands well 
above the mare and sufficiently firmly to permit the contents to be occasionally 
stirred. If the cellar is so situated that none of the above expedients are 
feasible, then do your best to cool the atmosphere by a liberal use of wet 
sacking about the cellar, enveloping your vats in the same material, and 
occasionally spraying them to keep up an evaporation. 
Wood being a bad conductor of heat, it is well to avoid using that material 
in the construction of fermenting vats. Excellent results have been obtained in 
Algeria by the use of enamelled iron vats; if these are not obtainable, ordinary 
