Source : Webster's Revised Unabridged Dictionary (1913)

Ferment \Fer*ment"\, v. t. [imp. & p. p. {Fermented}; p. pr. &
   vb. n. {Fermenting}.] [L. fermentare, fermentatum: cf. F.
   fermenter. See {Ferment}, n.]
   To cause ferment of fermentation in; to set in motion; to
   excite internal emotion in; to heat.

         Ye vigorous swains! while youth ferments your blood.
                                                  --Pope.

Source : WordNet®

fermenting
     n : a process in which an agent causes an organic substance to
         break down into simpler substances; especially, the
         anaerobic breakdown of sugar into alcohol [syn: {zymosis},
          {zymolysis}, {fermentation}, {ferment}]