If a person ate a food upon which one recites "Boreh Nefashot" after eating, such as fruits, or drank a beverage, and then left before reciting "Boreh Nefashot," he must recite a new Beracha before he resumes eating. Regardless of whether he resumes eating in his new location or returns to his original location, if he wishes to resume eating he must first recite a Beracha, such as "Ha’etz" over fruit or "She’hakol" over a beverage. On this point there is no difference of opinion among the Halachic authorities. However, according to the Shulhan Aruch (Orah Haim 178), a person in this case should first recite "Boreh Nefashot" and then recite a new Beracha before resuming eating. The Rama (Rabbi Moshe Isserles of Cracow, 1525-1572) disagrees, and rules that one may simply recite a new Beracha over the food, and the "Boreh Nefashot" he recites afterward covers all the food he had eaten.
Applying the rule of "Safek Berachot Le’hakel" (that we do not recite a Beracha in situations of Halachic uncertainty), the Halacha in this case is that one should not recite a Beracha Aharona before he continues eating, and should just recite a Beracha Rishona and then eat (or drink).
As discussed in a previous edition of Daily Halacha, if a person ate a Ke’zayit of bread, such that he is required to recite Birkat Ha’mazon, and then left before reciting Birkat Ha’mazon, he does not recite any new Berachot when he resumes eating. The Birkat Ha’mazon obligation binds him to his original location, and thus he does not have to recite any new Berachot if he continues eating. Seemingly, however, this should apply only if the person ate a Ke’zayit of bread and thus has an obligation of Birkat Ha’mazon. But if he ate less than a Ke’zayit, such that he does not – at least yet – have an obligation to recite Birkat Ha’mazon, he has nothing connecting him to his original location, and must therefore recite new Berachot if he resumes eating.
In truth, however, the Halacha regarding such a case is far from clear. Rabbi Bitan, in the English edition of Yalkut Yosef (Berachot, p. 80), notes that in the first edition of Halichot Olam (vol. 2, p 40), Hacham Ovadia rules that even if one ate less than a Ke’zayit before he left, he does not recite Berachot when he resumes eating. In later editions, however, this Halacha is omitted, suggesting that the Hacham retracted this ruling, and decided that if one ate less than Ke’zayit and then left he must recite new Berachot when he resumes eating – which is, in fact, the ruling of the Magen Abraham (Rabbi Abraham Gombiner, Poland, 1637-1682). The Hebrew edition of Yalkut Yosef, however, records the Hacham’s opinion in the earlier edition. Rabbi Bitan concludes that one who wishes to recite new Berachot in such a situation has opinions on whom to rely, but it would seem that one in fact should recite new Berachot, in accordance with the Magen Abraham’s opinion, and with the implication of the later editions of Halichot Olam.
Summary: If a person ate a food requiring "Boreh Nefashot" and left before reciting the Beracha, when he resumes eating he must recite a new Beracha before the food. If one ate a Ke’zayit of bread and then left before reciting Birkat Ha’mazon, he does not recite new Berachot when he resumes eating, but if he left after eating less than a Ke’zayit of bread, he must recite new Berachot before resuming eating.
