Challah 3:9-10

Challah 3:9

Similar to the case in 3:8, if gathered olives (which are liable to tithes) got mixed with olives left for the needy (of a kind that are exempt from tithes), or if the same scenario occurred with grapes, then if one can take tithes for the liable portion from other produce, he should do so. If this is not possible, he takes terumah and terumas maaser for the whole thing, plus first tithe and second tithe for the liable portion.

Challah 3:10

If one took leaven from wheat dough and put it into rice dough, if it tastes like the wheat, the dough is obligated in challah, otherwise it is exempt. If this is so, why did they say that any amount of tevel (untithed produce) mixed in with other produce renders it prohibited (a ramification of 3:8)? That’s only when it’s mixed in with its own kind of produce; when mixed in with another type, tevel only renders prohibited if it imparts taste.