716 EXPERIMENT STATION RECORD. 



of malic acid are present, the nraiiyl acetate exerts its in/lueuce upon the 

 sugars, and. tlierefore, when the ai)proximate amount of sugar or malic acid is 

 unknown some simple modifications must be made in the procedure. Numerous 

 tests illustrating the above points, as well as some malic acid determinations in 

 solutions (strawberry juice) containing an unknown amoiuit of malic acid, 

 accompany the description of the method. 



Principles and practice of cider making, B. T. P. P.arker {Jour. Inst. Brew- 

 ing, 11 (1911), No. 5, pp. Ji25-JfJil, figs. 2; abs. in Jour. Soc. Chetn. Indus., 30 

 (1911), No. IJi, pp. 915, 916). — Apples designed for cider production may be clas- 

 sified into a sour or sharp group, in which the malic acid content is above 0.45 

 per cent, a sweet class where the acidity is below 0.45 per cent and the tannin 

 below 0.2 per cent, and a bitter-sweet group in which the malic acid is below 

 0.45 per cent but in which the tannin content is above 0.2 per cent. The kind 

 of .luice obtained from a certain apple is never constant and will always be 

 foimd to differ with the seasons and the nature of the soil. 



"Attempts to obtain a more regular type of fermentation by the use of se- 

 lected yeasts have not led to very satisfactory results ; this is not surprising in 

 view of the variation in quality of the different juices due to the miscellaneous 

 character of the raw material employed. It is quite possible that if a more or 

 less standard quality of juice could always be used, fermentation with pure 

 cultures would give more satisfactory results than natural fermentation. There 

 are usually from 6 to 12 different kinds of yeasts naturally present in the juice; 

 some are not numerous and are soon crowded out. During the earlier stages 

 of fermentation, yeasts of the [Saccharomyces'] apicitlatiis type appear to be 

 most numerous, while elUpsoideus yeasts predominate at a later stage, and 

 when the fermentation is finished and the cider has partly matured, a number 

 of minute torula-like yeasts become conspicuous. 



"Acetification is one of the most troublesome disorders of cider and ropiuess 

 is also of common occurrence, but the most characteristic cider disease is that 

 known as ' sickness.' This disease is very liable to appear in sweet ciders Mur- 

 ing May and June. At present there is no satisfactory method of preventing 

 the disorder in cask, but the cider may be rendered less liable to sickness by 

 blending the sweet type of juice with juices which normally ferment more 

 rapidly, or by using a comparatively large proportion of apples of the sharp 

 class, or by bottling the cider at a veiy much earlier date than usual." 



The principles of wine making, F. T. Bioletti (California Sta. Bui. 213, 

 pp. 395-.'i-'f2, figs. 4)- — This bulletin discusses in detail the nature of wine, the 

 biological theory of wine making, causes of variation in character and quality, 

 the operations of wine making, the relation of micro-organisms, causes of fer- 

 mentation, the micro-organisms found in grapes and wine, and the control of 

 the micro-organisms before, during, and after fermentation. 



The signifi.cance of mineral salts in vinegar fermentation, PI. Wusten- 

 FELD (Dent. Essigindus., H (1910), No. 38, pp. 215, 216). — A discussion in 

 regard to the functions of various mineral salts in the vinegar fermentation 

 process. 



Paints; their service condition, E. F. Ladd and E. E. Ware (North Dakota 

 Sta. Bui. 92, pp. 113-202, figs. 42). — "In compiling this report on conditions 

 of test fences painted in 1906, 1907, 1908 and test houses painted in 1907, 1908, 

 1909, an endeavor has been made so to group the results as to bring together 

 paints of similar type, thus to facilitate the comparison of such similar types 

 under varying conditions, as well as to show the action of differing types under 

 identical conditions of exposure." See also previous notes (E. S. R., 22, p. 710; 

 23, pp. 168, 371, 692; 25, p. 115). 



