Alcoholic fermentation temperature control during

To show correlation between occurrence of malo-lactic fermentation and bacterial inoculation, and to show consistency of results among the control lots and inoculated lots, it is imperative that the division of lots be made before alcoholic fermentation. For red wines, great care must be taken to obtain equitable distribution of the crushed grapes in each of the lots. The inconsistency in the results mentioned above may have been caused by variation in amounts of grape skins during the alcoholic fermentation with the accompanying effect on fermentation temperature, sulfur dioxide concentration,. pH after pressing, and concentration of nutrients (55, 56). 

Mannitol. Whereas mannitic fermentations are seldom a problem where sulfur dioxide, pure yeasts, and temperature control are employed, Martucci (1941) has reported them in Argentina. He recommended control of the must acidity, since a high pH also favored such spoilage. A complicated polaiimetric procedure for mannitol (a sugar alcohol) in wines was presented by Salani (1937). Formation of mannite during dialysis of musts at low temperatures (8° to 10° C. (46.4° to 50° F.)) in the presence of chloroform was reported by Barbera (1933b) (possibly owing to enzyme action). 

Beer, on the other hand, is produced by more complex biochemical and technological processes, which all affect its flavor. Yeast amino acid metabolism, a key to the development of beer flavor as described earlier, is affected by process temperature and use of cell immobilization techniqnes. Therefore, technologies based on these features as well as other process conditions and strain selection have been developed to control beer flavor. The combination of immobilized yeast and low-temperature primary fermentation was found to produce beers with low diacetyl amounts, therefore indicating potential of low-cost industrial application since maturation is a high-energy-consuming process. Finally, Perpete and Collin showed that during alcohol-free beer production, the enzymatic reduction of worty flavor (caused by Strecker aldehydes) by brewer s yeast was improved by cold contact fermentation. 

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