(n.) The quality of being acescent; the process of acetous fermentation; a moderate degree of sourness.

acescency acid acidity acidness acidulousness acridity acridness acrimony animosity asperity astringence astringency bile bite bitingness bitter pill bitter resentment bitterness bitterness of spirit causticity causticness choler corrosiveness crabbedness cuttingness dourness dryness edge fierceness gall gall and wormwood gnashing of teeth greenness grip hard feelings harshness heartburning hyperacidity incisiveness keenness mordacity mordancy piercingness piquancy poignancy point pungency rancor rankling rigor roughness severity sharpness slow burn soreness sour sourishness sourness spleen stabbingness sting stridency stringency subacidity surliness tartishness tartness teeth trenchancy unripeness unsweetness vehemence verjuice vinegariness vinegarishness violence virulence