Definitions for "Souring"
Bacteria, mold, water, air, light, enzymes and some metals can accelerate souring. Souring results in the formation of free fatty acids, such as butyric acid and caproic acid, and the butter becomes soapy in flavor.
Keywords:  pasturing
pasturing
Keywords:  apple
Any sour apple.
Keywords:  becoming, process
the process of becoming sour