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Among 1 the advantages which result from the aeration of the 

 must, or mash of grapes, before it is turned into wine, the following 

 may be mentioned : 



(i.) The cooling down of hot must obtained from grapes 

 picked during the hottest hours of the day. 



(2.) A greater regularity in the progress of fermentation. 



(3.) Its earlier completion, hence less exposure to the air, and 

 therefore less risk of contamination by injurious 

 microbes which float in the air. 



(4.) The quicker clearing of the young wine. Aeration or 

 oxidation causing the precipitation into the lees of 

 some of those rapidly-decomposing white-of-egg-like 

 or albuminoid matters in the must, which afford a 

 favourite food for dangerous microbes. 



As an instance of this, I may just mention that in the Depart- 

 ment of Meurthe, in the North-West of France, where the grapes 

 contain much albuminoid matter, aeration is carried on systemati- 

 cally as one of the processes of wine-making. For this purpose the 

 must is thoroughly stirred by means of shovels, till the air is well 

 incorporated through its mass, and such wine, which is known as 

 mn de pelle (shovel -made wine), by reason of its superior quality, 

 sells for 20 per cent, more money than wines made from similar 

 must, but according to the ordinary methods of verification. The 

 cost of this very simple but laborious operation is reckoned at 

 barely Id. more per gallon. With the modern mechanical appliances, 

 this cost is considerably reduced, whilst the resulting advantages 

 are decidedly important. Of late years a machine constructed on 

 the principle of a cream- separator, and known as the aero-crushing 

 grape mill, has been introduced, which effects this work with great 

 thoroughness. Such a machine, I have no doubt, should prove a 

 great success in hot countries, where the grapes mature very 

 quickly, and more especially on rich alluvial land, the percentage of 

 these nitrogenous matters increases very much, and it is of great 

 importance that any of the surplus of it, beyond what is necessary for 

 the use of the yeast fungi, should be removed. Some grapes are 

 exceeding rich in these bodies, notably the riesling and the 

 muscats. 



Aeration is more especially suitable to white wine. One of its 

 actions on must is to bring about the precipitation of the colouring 

 matter. A ready method of securing it is by means of a pump, 

 through which a current of air is injected into' the liquid. A rose 

 is attached at the end of the delivery pipe. This is done for 10 to 

 12 minutes, but must not be overdone, so as not to impart to the 

 wine a yellowish colour. With a little practice, the exact time when 

 aeration should cease is soon known. If every five minutes a little 

 must is run through some filter paper, the pumping is stopped 

 directly the liquid ceases to show a rosy tint. A brownish-looking 

 precipitate is collected on the filter. Subsidising is necessary after 

 aeration. One disadvantage of aeration is that it promotes the 



