Gyle tun

from The Collaborative International Dictionary of English v.0.48

Gyle \Gyle\ (g[imac]l), n. [F. guiller to ferment. Cf.
   {Guillevat}.]
   Fermented wort used for making vinegar.
   [1913 Webster]

   {Gyle tun} (Brewing), a large vat in which wort ferments.
      [1913 Webster]