D'Hevi'euse Air Treatment. 



101 



now AIR-TREAT.MENT IS APPLIED TO 

 FLUIDS. 



To impregnate a fluid with a gas, 

 we admit the gas below, that it may 

 rise upwards through the fluid. Ac- 

 cordingly the air, to act most effectu- 

 ally, is admitted into the fluid in a 

 divided state by perforated pipes or 

 mouth pieces, sunk near the bottom 

 of the vessel, impelled by an air-force 

 pump. Air-treatment of a hot fluid 

 for purification from albumen requires 

 a vigorous and continuous current of 

 air frequently for hours to coagulate 

 all albumenous parts ; for fermenta- 

 tion however, periodical gentle cur- 

 rents are sufliicient. 



TO WINE ESPECIALLY, 



A vigorous fermentation has been 

 found the most satisfactory for must 

 as well as other mash, and a suffi- 

 ciently high temperature (75* to 85° 

 P.) is essential. Fluctuation of tem- 

 perature should be avoided as always 

 detrimental. When the must is 

 warmed (in a gathering tank) to about 

 65° to 70'" P., the tanks or casks filled, 

 the temperature steadily maintained, 

 air is impelled vigorously for some ten 

 minutes, and unless sugar is added 

 a foaming up by a rising scum, will 

 soon take place. After this subsides 

 rfrom six to ten hours) air is gently 

 impelled two or three times each day 

 for about five minutes at a time, till 

 the fermentation is finished, which is 

 accomplished at the stated tempera- 

 ture in from five to fourteen daj's 

 without fail. The air pipes (of block 

 tin) are introduced into the casks 

 thi-ough the bung-hole, in tanks from 

 above, and, where pulp is worked for 

 red wine, should be stationary for the 



opei'ation. The tendency to clarify 

 appears at once when the carbonic 

 acid gas ceases to foi*m. A few days 

 later the still somewhat turbid wine 

 may be drawn off to settle in casks, 

 bunged up, and a few weeks later will 

 be found clear, of free ripe taste, sub- 

 ject to no after fermentation or other 

 wine disease, free of ground taste, and 

 fit to be shipped to any part of the 

 world without more risk than old well 

 stored wines. Scrupulous cleanliness, 

 sweet vessels, etc., are, of coarse, al- 

 ways essential. 



With proper care and judgment, all 

 wines can bo quickly finished by air- 

 treatment, that were previously but 

 imperfectly fermented in the usual 

 mode, even diseased wines (if free 

 from acetic acidification) restored. 

 But no general directions can in these 

 cases guarantee success to careless or 

 inexperienced persons. It should, 

 however, be borne in mind, that in all 

 the above cases, the object is the re- 

 moval of the excess of gluten by a 

 quickly started and lively (though 

 brief) fermentation, for which the 

 presence of some sound and active 

 ferment, sufficient sugar, proper heat 

 and air are essential. Addition of 

 ferment may, therefore, be required, 

 or of sugar, the determination of the 

 proper proportions of either, the 

 work of experience and judgment. 

 The ferment — if sound wine yeast or 

 another kind — should be brought into 

 full vigorous action before it is added 

 to the quickly-warmed wine (of 70 to 

 75** P.), this temperature retained 

 unchangeable during the few days of 

 subsequent finishing fermentation. 

 All subsequent processes are, howev- 

 er, obviated by the use of air-treatment 



