3,335. Threshing Terumah Produce
Terumos 11:28
It is considered meritorious to crush produce that grew from terumah. Threshing it presents a problem since one can’t allow his animal to eat it, nor may one muzzle his animal while it’s threshing. In such a case, one ties a pail of regular grain of the same type around the animal’s neck while it’s threshing. In this way he violates neither prohibition.
Terumos 12:1
It is prohibited to render terumah from Israel ritually unclean, the same as other holy things. One may neither render it ritually unclean nor ruin it. Rather, ritually clean terumah is eaten and ritually unclean terumah is burned as fuel. One may allow terumah from outside of Israel to be rendered ritually unclean, even with a Biblical form of impurity. Even though it’s only unclean because of the impurity from outside of Israel, which is Rabbinic in origin, this is permitted because separating terumah outside of Israel is by Rabbinic enactment. Therefore, a woman who is a niddah may separate challah outside of Israel. She is only cautioned not to eat it; touching it poses no problem.