The Sages forbade the bread of a non-Jew (פת עכו״ם) for fear of the closeness that leads to intermarriage (חתנות) — only the bread of the 5 grains. The major distinction: the bread of a professional baker (פלטר), on which many places are lenient (especially without a Jewish baker, or if the bread is finer), vs. the bread of a private person (בעל הבית), which is stricter; the status follows the moment of baking, and the Jew's participation in the oven (חיתוי / throwing a chip) permits it; plus biscuits, cakes, mixtures and bitul (Shulchan Aruch, Yoreh De'ah 112 — 16 se'ifim)
אָסְרוּ חֲכָמִים לֶאֱכֹל פַּת שֶׁל עוֹבְדֵי כּוֹכָבִים מִשּׁוּם חַתְנוּת. וְלֹא אָסְרוּ אֶלָּא פַּת שֶׁל חֲמֵשֶׁת מִינֵי דָגָן, אֲבָל פַּת שֶׁל קִטְנִית וְשֶׁל אֹרֶז וְדֹחַן אֵינוֹ בִּכְלַל פַּת סְתָם שֶׁאָסְרוּ.
The Sages forbade eating the bread of non-Jews on account of חתנות (the closeness leading to intermarriage). They forbade only the bread of the five species of grain; but bread of legumes, rice and millet is not included in the bread they forbade.
Shulchan Aruch, Yoreh De'ah 112:1LEVEL 01
Hebrew text of the 16 se'ifim with a fluent English translation. The prohibition of the bread of non-Jews (חתנות, the 5 grains), the baker's bread (פלטר) vs. the private person's (בעל הבית), the Jew's participation in the oven (חיתוי), biscuits and bitul explained with practical cases.
📖 StudyLEVEL 02
In-depth pilpul: the sugya of Avoda Zara, the yesod of the פלטר leniency (שעת הדחק or a decree that did not spread), בתר תחילתו, the חיתוי as a היכר against a tangible prohibition, the Shach's debate on the Jew's act of baking (אפייה), חקירות and נפקא מינות.
📖 StudyLEVEL 03
Comparative tables (פלטר / בעל הבית, with or without a Jewish baker, finer bread, חיתוי / קיסם), golden rules, classic pitfalls (לא פלוג, בתר תחילתו, eggs בעין, bitul be-rov, איבה) and memorization of the 16 se'ifim.
📖 StudyLEVEL 04
The practical halacha according to the Shach, Taz, Pri Megadim and Pitchei Teshuva, then the Sephardic poskim (Yabia Omer, Yalkut Yosef, Or LeTzion) and Ashkenazi poskim: bakery and supermarket bread (פת פלטר), participation in baking, industrial biscuits and cakes, and the status during the Aseret Yemei Teshuva. Note: the Shulchan Aruch HaRav does not deal with this siman — this is a level of psak, not "Daat HaRav".
📖 StudyAccording to the Shulchan Aruch (YD 112:1), the Sages forbade eating the bread of non-Jews on account of חתנות (the social closeness that leads to intermarriage). The Rama adds that the prohibition applies even where there is no actual concern of חתנות (לא פלוג). They forbade only the bread of the five species of grain (חמשת מיני דגן); bread of legumes (קטנית), rice or millet is not included. For practical halacha, consult your Rav.
This is the major distinction of se'ifim 2-8. Many places are lenient on the bread of a professional baker (פלטר), especially where there is no Jewish baker, or if his bread is finer or of a different type. The bread of a private person (בעל הבית) is stricter, since eating it leads to dining at his home — except where there is no פלטר at all (se'if 8). The criterion is purpose: made to sell = פלטר; made for oneself = private person. For practical halacha, consult your Rav.
According to se'ifim 9-12, if the Jew takes part in the baking — he stirred the fire (ניער האש), threw a single chip (קיסם) into the oven, or even blew on the fire (נפיחה) — all the bread in it becomes permitted, since the essential point is only a sign (היכר) recalling that the bread of non-Jews is forbidden. The חיתוי remains effective as long as the bread still needs the oven and is improved by it. For practical halacha, consult your Rav.