PT  - JOURNAL ARTICLE
AU  - W. M. Ingledew
AU  - Ralph E. Kunkee
TI  - Factors Influencing Sluggish Fermentations of Grape Juice
AID  - 10.5344/ajev.1985.36.1.65
DP  - 1985 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 65--76
VI  - 36
IP  - 1
4099  - http://www.ajevonline.org/content/36/1/65.short
4100  - http://www.ajevonline.org/content/36/1/65.full
SO  - Am J Enol Vitic.1985 Jan 01; 36
AB  - 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.