In the language of the Sages, tevel refers to produce from which terumot and ma’asrot have not yet been separated. The word tevel may be understood as tov-lo – “not good” – meaning that the produce is not yet fit to eat. Demai refers to produce about which there is uncertainty: perhaps terumot and ma’asrot were separated from it, and perhaps not. The word demai is Aramaic, meaning, “What is this?” In other words, the produce stands in question: were the required separations performed or not?
In the time of the Sages, most amei ha’aretz separated terumot and ma’asrot, but some did not do so properly. The Sages therefore gave produce bought from them the status of demai. Since teruma gedola was commonly separated even by amei ha’aretz, the Sages did not require one to separate it from demai. They did require one to separate ma’aser rishon, terumat ma’aser, and either ma’aser sheni or ma’aser ani.
Even so, the Sages did not require one to distribute the ma’aser rishon to a levi or the ma’aser ani to a poor person. Since these gifts are monetary obligations, they follow the general rule: “One who seeks to take money from another bears the burden of proof.” Unless the levi or poor person can prove that the ma’asrot were not already separated from this produce, the owner need not give them the gifts. He must, however, separate terumat ma’aser from the ma’aser rishon and give it to a kohen, because terumat ma’aser has sanctity and may not be eaten by a non-kohen. Similarly, since ma’aser sheni has sanctity, it must be separated and eaten in Jerusalem in purity.
One does not recite a berakha when separating terumot and ma’asrot from demai, nor when redeeming its ma’aser sheni, following the well-known rule that we are lenient in cases of doubt concerning berakhot (see MT, Laws of Ma’aser 9:1–4). If one redeems ma’aser sheni of demai, he need not add the additional fifth (MT, Laws of Ma’aser Sheni and Neta Reva’i 5:4).
Today, when there is doubt whether produce has been tithed, that doubt includes teruma gedola as well, since even that is generally not separated by amei ha’aretz. Therefore, one separates all the terumot and ma’asrot without a berakha. As explained above, the monetary gifts – ma’aser rishon and ma’aser ani – need not be given to the levi or the poor person. The sanctified portions, however – teruma gedola and terumat ma’aser – must be set aside out of doubt, wrapped, and discarded respectfully. Ma’aser sheni must likewise be redeemed onto a peruta.
Whenever one is unsure whether the produce before him belongs to a ma’aser sheni year or a ma’aser ani year, he should separate both out of doubt and say: “If this produce requires ma’aser ani, this shall be ma’aser ani; and if it requires ma’aser sheni, this shall be ma’aser sheni.” He then redeems the ma’aser sheni onto a peruta and gives the ma’aser ani to a poor person. One who wishes to be lenient may separate ma’aser sheni alone.[18]
