Q. What bracha do you make on the peel of an esrog that was turned into some kind of jam, if you can still recognize the peel?

A. Mishna Berura (202: 19) cites Mogen Avrohom that on unripe small fruits that are bitter and inedible, once you have cooked and sweetened them, you recite Shehakol. However in Shaarey Tziyon (ibid. 19) quotes Olelos Efraim saying that as long as you eat the fruit itself even if it was bitter and inedible before you sweetened it, you recite Bore Peri Hoetz. Poskim also disagree on what brocho to recite over just the peel by itself. Ben Ish Chai (par. Pinchas 1: 4) presents three different opinions; Hoetz, Hoadomo and if sweetened Shehakol. However Taz (205: 3), Chasam Sofer (O.H. 207), Kaf Hachaim (202: 55) and Ponim Meiros (1: 65) and others maintain that even when sweetened the brocho is Hoetz. Zichron Yehuda (p. 23) quoting Imrei Eish adds as a reason for Hoetz is that the Torah calles the fruit P’ri Eitz and people plant esrogim having in mind that after using them for the mitzvah, they will eat them sweetened.

Horav Shlomo Miller’s Shlit”a opinion is that when the esrog was prepared and sweetened the brocho for the white fleshy parts together with the thin green peel is Hoetz, as this are the only parts that are eaten when sugared.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a