Terumot and ma’asrot should be separated from the best produce, as the Torah states: “When you raise up its choicest part from it” (Bamidbar 18:32). This means that, whenever the gifts will actually be given to a kohen or levi, one should choose the superior portion. If, however, no kohen or levi is available, and there is concern that the best ripe produce will spoil before it reaches them, it is better to separate produce that will keep longer, even if it is not the finest. If one separated inferior produce, the separation is valid, and the remaining produce may be eaten (Mishna, Terumot 2:4–6; MT, Laws of Terumot 5:1).
Today this distinction is especially significant. Since everyone today is presumed to carry corpse-impurity and kohanim cannot eat teruma in purity, all produce is effectively ‘inferior’ from the standpoint of the gift — and one may therefore separate from lower-quality produce from the outset. Ma’aser rishon, however, is given to a levi, and ma’aser ani is given to the poor. Since both may still be eaten, they should be separated from better-quality produce (SA YD 331:52; Vilna Gaon, Bi’ur ha-Gra 95; see below, sections 10–11).[1]
Terumot and ma’asrot must also be separated from the same species. If one separates from one species for another, the separation is void, and he must separate again from the proper species. The guiding test is the law of kilayim: if two kinds may not be planted together as vegetables, or grafted together as trees, they are considered two species for terumot and ma’asrot as well. One may not separate from one for the other, even from the superior species for the inferior one.
However, different varieties of the same species may be separated for one another. Thus, all varieties and colors of grapes are one species, and all varieties and colors of cabbage are one species. Peaches and nectarines are likewise one species. Oranges and grapefruits, however, are two species (Mishna, Terumot 2:6; MT, Laws of Terumot 5:2–3; Mishpat Kohen §25; see above, 3, note 4).
[1]. Today, since kohanim do not eat teruma, one may separate teruma for wine from the liquid portion of wine sediment. The amount separated is calculated according to that liquid alone, which some estimate at roughly sixty percent (Divrei David 4, YD 61). Mishpetei Eretz 8:23 expresses hesitation, because that amount is difficult to calculate precisely. This concern is difficult to understand, however, because one can avoid the doubt by calculating conservatively.
The Sages ruled that one may not give the kohen or levi a gift that still requires significant processing. Therefore, if one separated terumot and ma’asrot from sheaves for kernels, from olives for oil, or from grapes for wine, the separation is void. In each case, the recipient has been disadvantaged, because he must now process the gift before it can be used. The owner must therefore separate terumot and ma’asrot again after the processing is complete (Mishna, Terumot 1:4; MT, Laws of Terumot 5:18).
If the owner already separated terumot and ma’asrot in this way, and the kohen and levi are willing to receive their gifts in the unprocessed form – sheaves, olives, or grapes – then after the fact, the separation is valid and the produce is no longer considered tevel (Rash; Rosh; Radvaz). R. Kook maintains that today, since kohanim cannot eat teruma in any case, the separation is effective even without their consent. Some disagree regarding ma’aser; see Ha-Ma’aser Ve-ha-Teruma 5:14 and Ma’adanei Eretz, Terumot 5:18:3.
When it comes to grapes and wine, the determining factor is intent at the moment the obligation of terumot and ma’asrot first applies. Therefore, if one bought grapes to eat, separated terumot and ma’asrot, and only afterward decided to make them into wine, he need not separate again (Mishna, Terumot 1:9; MT, Laws of Terumot 5:20). The original separation was effective, because the obligation had already applied to the grapes as fruit meant for eating.
The same principle applies in the opposite direction. If one bought grapes to eat and then decided to make wine before separating terumot and ma’asrot, he may no longer snack on them casually. Since the obligation took effect when he bought them for eating, that obligation remains even after he decides to process them into wine (Ma’adanei Eretz, Terumot 1:14:7).
