RT Journal Article SR Electronic T1 Experiments with Controlled Fermentations. IV JF American Journal of Enology and Viticulture JO Am J Enol Vitic. FD American Society for Enology and Viticulture SP 5 OP 14 DO 10.5344/ajev.1960.11.1.5 VO 11 IS 1 A1 C. S. Ough A1 M. A. Amerine YR 1960 UL http://www.ajevonline.org/content/11/1/5.abstract AB Color extraction by stirring was found more efficient than the other methods of agitation tested, but causes more tannin to be extracted. Pumping over was determined to be more effective than punching down, and pressure treatments were all about equally effective.Temperature treatments were found effective in increasing color extraction, but also increased tannin extraction to some degree.The temperature differences inside the tanks during fermentation of red wines were demonstrated to be quite large, even with submerged-cap fermentations in a relatively small jacked tank.The use of bentonite during fermentation at the rate of 12.5 lbs per 1000 gals. was determined to have some clarifying effect on the wine, increased filter speed, and also lightened the color of the wine slightly. The results were inconclusive as to the removal of nitrogen by this treatment.Pressure-controlled fermentations with white musts produced wines having higher pH's and volatile acids, and lower taste score ratings than wines produced in temperature-controlled fermentations.Stirring or not stirring white must under low carbon dioxide pressure (20 psig) was found to have no advantage over an unstirred atmospheric fermentation.