The Collaborative International Dictionary of English v.0.48:

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 or fermentation in; to set in motion; to
   excite internal emotion in; to heat.
   [1913 Webster]

         Ye vigorous swains! while youth ferments your blood.
                                                  --Pope.
   [1913 Webster]

WordNet (r) 3.0 (2006):

fermenting
    n 1: 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, fermenting, ferment]