2,438. Nullification in 100:1

Maachalos Assuros 15:12

The Rambam opines that even in cases where there’s a means to permit something prohibited, if the prohibited thing gets mixed with something of a different kind and its taste isn’t discernable, it’s permitted; the ability to render the prohibited thing permitted doesn’t make it more stringent than untithed produce. Untithed produce can be fixed (by taking tithes) but if it gets mixed with a different kind, it’s permitted if it can’t be tasted, as we have discussed. Don’t wonder why this isn’t the case with chometz on Pesach; chometz is different because Exodus 12:20 prohibits “anything leavened.” This is why they were stringent about chometz, as discussed above.

Maachalos Assuros 15:13

The Sages set the following measures for nullification: trumah, trumas maaser, challah and bikkurim are nullified in a mixture 101 times their volume (i.e., a ratio of 100:1), plus one must separate the appropriate portions from them. These items combine with one another. Similarly, a piece of showbread that was mixed with pieces of regular bread is nullified in a mixture 101 times its volume. Therefore, if a seah of flour from one of these, or from any combination of them, falls into 100 seah of regular flour and gets mixed in, one should separate a seah from the mixture for the seah that fell in and the rest is permitted to non-kohanim. If it fell into less than 100 seah, then the whole thing is meduma (a trumah mixture prohibited to non-kohanim).