It is written:¹ 23:14. "And bread, and roasted grain and fresh grain² says “carmel” is grain roasted in its stalks. you shall not eat until this very day" etc. This means that it is forbidden to eat of any of the five species [of grain] [wheat, barley, oats, spelt, rye] from the new grain crop until after the offering of the omer, which was offered on the sixteenth day of Nissan. In a time when there is no omer [as in our times], it is forbidden to eat the new crop the entire day. In countries outside Eretz Yisroel, where two days of Yom Tov are celebrated, because of the doubt (of the actual day of Yom Tov,) it is also forbidden the entire seventeenth day until the beginning of the night of the eighteenth day. Grain which had been sown and taken root before the sixteenth day of Nissan, is made valid for use by (bringing) the omer, and it may be eaten immediately after it is harvested. However, if it did not take root before the sixteenth of Nissan, it is forbidden until next year's omer is brought.

footnotes: ¹ Leviticus ² The Chinuch

According to most of the greatest Poskim,³—Ravia, Hagahos Maimonee, Ritvah, Shulchan Aruch, etc. However, the Ohr Zarua is inclined, when there is a doubt about a particular product from outside Eretz Yisrael, to consider it a Rabbinical injunction and is lenient. The Trumas Hadeshen says grain of a non-Jew’s fields outside Eretz Yisroel is “chodosh” only as a Rabbinical injunction and Bach-Riva permit it entirely. Anyone who can, should be strict with regard to “chodosh” outside Eretz Yisroel, as most poskim hold it is de’oraisa, and certainly if you know it is “chodosh,” you should not eat it, since, even most of those who say it is not a de’oraisa, say it is a Rabbinical injunction (Biur Halacha 489:10) the above prohibition, even outside Eretz Yisroel, is a Scriptural prohibition. Therefore we must pay careful attention to grain crops that are sometimes sown after Pesach or so close to Pesach that it has not taken root before the sixteenth of Nissan, such as barley and oats, and in some places also wheat, for they are forbidden until after the seventeenth of Nissan of the next year. (If it had taken root on the sixteenth day of Nissan, it is permitted at the beginning of the seventeenth night of Nissan of the next year in any event.) Also the beer⁴ are lenient with regard to beer and all malt products. made from this grain, is forbidden until after the next Pesach. Also the lees are forbidden. If dough was leavened with it, even if the dough was made from the old grain crops, the entire dough is forbidden due to the yeast. Concerning crops about which there is a doubt whether it is old or new, you should consult a Poseik.

footnotes: ³ Rif, Rambam, Smag, Rosh, Ittur, Mordecai ⁴ Some Poskim

Some Poskim maintain that the prohibition of eating the new crops applies only to grain that grew in the field of a Jew. Even if the field belongs to a non-Jew, but it has been leased by a Jew, the law of new crops applies to this grain. However, if the grain grew in the field of a non-Jew, the prohibition of new crops does not apply. Many people rely on this in difficult circumstances.⁵ Nevertheless, if the grain grew in the field of a Jew, it is not permitted at all. Most Poskim disagree, and maintain that even grain that grew in the field of a non-Jew is subject to the prohibition of new crops; and a blessing will come upon one who is strict about it.⁶” is only if grown outside Eretz Yisroel, i.e., “chodosh” in Eretz Yisroel is unequivocally prohibited de’oraisa, with all the ramifications.

footnotes: ⁵ See footnote 3. ⁶ All discussion of leniency pertaining to “chodosh