3,349. Superior and Inferior Produce
Terumos 13:6
Let’s say that a seah of terumah fell into 100 seah of secular produce. Before a seah of the mixture can be removed, a second seah of terumah falls in. If the person knew about the first seah before the second fell in, the mixture is not rendered meduma. In such a case, he removes two seah and the rest is permitted to non-kohanim. Since a seah should have been removed, we act as if it had been removed. If he didn’t know about the first seah until after the second fell in, then the mixture is rendered meduma, the same as if two seah fell in at once.
Terumos 13:7
The refuse of terumah doesn’t combine with it to render secular produce prohibited. The refuse of secular produce, however, does combine with it to nullify terumah in a mixture. Let’s take the example of a seah of superior terumah wheat that fell into 100 seah of inferior secular wheat, and then the owner grinds the whole thing. Even though there’s a lot of bran in the secular produce and only a little in the terumah, meaning that the flour of the terumah is more than 1/100 of the flour from the secular wheat, it is nevertheless nullified because we measure the flour with the bran and it’s cumulatively 101 times the volume of the terumah. However, if a seah of inferior terumah wheat falls into just under 100 seah of superior secular wheat and the owner grinds it all, the terumah flour will be 1/100 the volume of the secular flour. The terumah is therefore nullified in mixture 101 times the volume of the terumah because the percentage of secular produce went up, while that of the terumah went down.