Ĥanuka was instituted as a holiday of praise and thanksgiving. Nonetheless, unlike Purim, there is no obligatory mitzva to partake in a festive meal. On Purim, we commemorate our enemies’ attempt to destroy our bodies by rejoicing physically, by eating and drinking. In the Ĥanuka story, however, the Jewish people experienced a spiritual victory. The Greeks enacted decrees only against Torah observance; one who complied and conducted himself like a Greek was safe. Therefore, the main idea of Ĥanuka relates to the spirit, so we thank and praise God for helping us preserve the Torah and the mitzvot (Levush).
Even though one is not obligated to prepare festive meals on Ĥanuka, many poskim maintain that one fulfills a mitzva by partaking in festive meals, in order to rejoice over the salvation that God performed for the Jews “in those days, at this time.” Some say that the Sages enjoined us to give thanks and recite Hallel over the spiritual salvation, but it is still appropriate to eat festive meals in commemoration of the rededication of the Temple.
In practice, we partake in festive meals on Ĥanuka, during which we share words of Torah and sing songs of praise to God. This way, the meals are considered se’udot mitzva according to all opinions. Moreover, by discussing Torah matters, the meals assume the special character of Ĥanuka, which is mainly spiritual joy, and through this the joy carries over to the meal.
There is a custom to eat dairy on Ĥanuka, in commemoration of the miracle that occurred through such foods. Yehudit, the daughter of Yoĥanan the High Priest, fed the enemy general dairy foods and killed him after he fell asleep, bringing salvation to the Jews. Even though this story happened before the events of Ĥanuka, Yehudit’s act of courage emboldened the Hasmoneans later on, giving them the strength to rebel against the Greeks. Therefore, her bravery is connected to the miracle of Ĥanuka. There is also a custom to eat foods fried in oil, like sufganiyot (fried doughnuts) and latkes (potato pancakes).
. The custom of eating dairy is mentioned by Ran (Shabbat 21b), Rema 670:2, and other Rishonim and Aĥaronim. According to many authorities, the episode of Yehudit did not take place at the same time as the Maccabean revolt. Ben Ish Ĥai, Vayeshev 24 explains that since her story also involved a Greek king who tried to force the Jews to abandon their faith, the Sages appended the custom commemorating this miracle to the holiday of Ĥanuka. I added another explanation in the main text above. Another minor custom, which is mentioned in a few books, involves eating foods fried in oil. Rabbeinu Maimon, Rambam’s father, writes (in his commentary on Ĥanuka) that one should not treat any custom lightly, even a minor one like eating sufganiyot, for one should not denigrate the customs of our people.