draff
From The Oxford Companion to Spirits & Cocktails
is the Scottish term for the spent grain left after the fermented wort has been drawn off for making whisky. It is often used as feed for farm animals. See distillers’ dried grains (DDG); whisky, scotch;, wort.
This definition is from The Oxford Companion to Spirits & Cocktails, edited by David Wondrich (Editor-in-Chief) and Noah Rothbaum (Associate Editor).