Q. Is it permitted to light a menorah with olive oil or vegetable oil without a hechsher, when traveling and no other oil is available? Is it better to light then with candles?
A. Some Poskim maintain that one should use for Chanuka lights only oil that is “min hamutar bepicha” or kosher for eating (Shenos Chaim 218, see Sdei Chemed – Chanuka 12). However, most Poskim disagree since it is only a rabbinical mitzva and has no inherent kedusha (Pri Megodim 32: 28, Noda Beyehuda 2: 3, Beis Yitzchok Y.D, 1: 145, Sdei Chemed ibid. et. al.).
Maharsham (9: 39) recommends that on the onset one should be stringent and use for Chanuka lights only kosher oil, since we are mehadrin min hamehadrin or comply with the maximum degree of observance when dealing with this mitzva. See question 682 in regards to lighting with oil that was left uncovered overnight.
There are non-Kosher oils, such as the product of orla or one that contains meat and milk cooked together, that one may not use at all, since besides being prohibited for eating, one cannot derive any benefit from them (Mishna Berura 673: 2). However, some Poskim maintain that one may use them if no other oil is available (Igrois Moshe O.H. 1: 191, Piskei Teshuvos ibid. n. 12).
Horav Shlomo Miller’s Shlit’a opinion is that one may light the menorah with olive or vegetable oil that has no hechsher and it is preferable to candles.
The Rov mentioned that the Talmud (Shabbos 20b) teaches that you may not use “shemen kik” or the oil made from a non-kosher animal, but you may use it for Chanuka (ibid. 21b), proves that non kosher oil is permitted for Chanuka.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a