3,347. Meduma

Terumos 13:2

If a seah of terumah falls into less than 100 times its volume of secular produce, the mixture is called meduma. It must be sold to a kohein at the price of terumah (which is cheaper than secular produce) except for one seah (which is given to a kohein). This is only the case when produce mixes with the same kind of produce; if one type of produce gets mixed with a different type, then it depends on whether the taste of the terumah can be discerned. If the whole mixture tastes like the terumah, then it's all meduma and must be sold to kohanim except for the value of the terumah. If the whole mixture tastes like the secular produce, then it is all permitted to non-kohanim.

Terumos 13:3

Let’s say that a seah of terumah fell into 100 seah of secular produce. One seah of the mixture was removed, and then that seah fell into other produce. The mixture’s status as meduma is determined by the percentages. Similarly, let’s say that a seah of terumah fell into less than 100 seah, rendering the whole mixture meduma. Some of that mixture then fell into different produce. This mixture’s status as meduma is likewise determined by the percentages. Therefore, let’s say that ten seah of terumah fell into 90 seah of secular produce, thereby rendering the whole mixture meduma. If ten seah of this mixture falls into less than 100 seah of secular produce, that mixture is likewise meduma. This is because the ten seah of the first mixture included at least one seah of terumah. If less than ten seah of terumah falls into the first mixture, the new mixture isn’t meduma.