Source : Webster's Revised Unabridged Dictionary (1913)

Brewing \Brew"ing\, n.
   1. The act or process of preparing liquors which are brewed,
      as beer and ale.

   2. The quantity brewed at once.

            A brewing of new beer, set by old beer. --Bacon.

   3. A mixing together.

            I am not able to avouch anything for certainty, such
            a brewing and sophistication of them they make.
                                                  --Holland.

   4. (Naut.) A gathering or forming of a storm or squall,
      indicated by thick, dark clouds.

Brew \Brew\, v. t. [imp. & p. p. {Brewed}; p. pr. & vb. n.
   {Brewing}.] [OE. brewen, AS. bre['o]wan; akin to D. brouwen,
   OHG. priuwan, MHG. briuwen, br?wen, G. brauen, Icel. brugga,
   Sw. brygga, Dan. brygge, and perh. to L. defrutum must boiled
   down, Gr. ? (for ??) a kind of beer. The original meaning
   seems to have been to prepare by heat. [root]93. Cf. {Broth},
   {Bread}.]
   1. To boil or seethe; to cook. [Obs.]

   2. To prepare, as beer or other liquor, from malt and hops,
      or from other materials, by steeping, boiling, and
      fermentation. ``She brews good ale.'' --Shak.

   3. To prepare by steeping and mingling; to concoct.

            Go, brew me a pottle of sack finely.  --Shak.

   4. To foment or prepare, as by brewing; to contrive; to plot;
      to concoct; to hatch; as, to brew mischief.

            Hence with thy brewed enchantments, foul deceiver!
                                                  --Milton.

Source : WordNet®

brewing
     n : the production of malt beverages (as beer or ale) from malt
         and hops by grinding and boiling them and fermenting the
         result with yeast