TY - JOUR T1 - Factors Influencing Sluggish Fermentations of Grape Juice JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 65 LP - 76 DO - 10.5344/ajev.1985.36.1.65 VL - 36 IS - 1 AU - W. M. Ingledew AU - Ralph E. Kunkee Y1 - 1985/01/01 UR - http://www.ajevonline.org/content/36/1/65.abstract N2 - Attempts to overcome sluggish (very delayed or incomplete) vinifications were made by application of previous brewing and enological findings regarding requirements for oxygen and other nutrients. Ruby Cabernet juice, and a Chardonnay juice which was known to give an incomplete fermentation commercially, were totally end-fermented in only seven days at 14°C when large amounts of assimilable nitrogen and small amounts of headspace air were provided. Restriction of oxygen by nitrogen gas flushing of the headspace resulted in protracted, sluggish-to-stuck fermentations. Air and free amino nitrogen additions stimulated the duration of active yeast growth and final cell mass, thereby enhancing fermentation rates. Indications as to the timing of aeration and the concentration of yeast food required to prevent sluggish fermentations are provided. ER -