▁to ▁descend ▁into ▁decre p itude ▁where ▁the ▁fruit ▁t ast es ▁h ollow ▁and ▁weak ▁while ▁the ▁wine ' s ▁acid ity ▁becomes ▁dominant . ▁ ▁The ▁natural ▁est er ification ▁that ▁takes ▁place ▁in ▁w ines ▁and ▁other ▁alco hol ic ▁be ver ages ▁during ▁the ▁ag ing ▁process ▁is ▁an ▁example ▁of ▁acid - catal ys ed ▁est er ification . ▁Over ▁time , ▁the ▁acid ity ▁of ▁the ▁ac etic ▁acid ▁and ▁t ann ins ▁in ▁an ▁ag ing ▁wine ▁will ▁catal yt ically ▁pro ton ate ▁other ▁organ ic ▁ac ids ▁( including ▁ac etic ▁acid ▁itself ), ▁encourag ing ▁eth an ol ▁to ▁react ▁as ▁a ▁nucle oph ile . ▁As ▁a ▁result , ▁eth yl ▁ac et ate ▁– ▁the ▁est er ▁of ▁eth an ol ▁and ▁ac etic ▁acid   – ▁is ▁the ▁most ▁abund ant ▁est er ▁in ▁w ines . ▁Other ▁combinations ▁of ▁organ ic ▁alco h ols ▁( such ▁as ▁phen ol - cont aining ▁comp ounds ) ▁and ▁organ ic ▁ac ids ▁lead ▁to ▁a ▁variety ▁of ▁different ▁est ers ▁in ▁w ines , ▁contrib uting ▁to ▁their ▁different ▁flav ours , ▁sm ells ▁and ▁t ast es . ▁Of ▁course , ▁when ▁compared ▁to ▁sul fur ic ▁acid ▁conditions , ▁the ▁acid ▁conditions ▁in ▁a ▁wine ▁are ▁m ild , ▁so ▁yield ▁is ▁low ▁( o ften ▁in ▁t enth s ▁or ▁hundred th s ▁of ▁a ▁percentage ▁point ▁by ▁volume ) ▁and ▁take ▁years ▁for ▁est er ▁to ▁accum