Q. What is the proper way of dealing with the leftover oil that wasn’t consumed in the cups of the Chanuka lights. Should one use it again next night and just add some more fresh oil, or is it more correct to properly clean the Menorah and place fresh oil completely inside?
A. Tur (677), Yosef Ometz (1075) and others maintain that it should be used next night. Hisorerus Teshuva explains two reasons why. One is that since it is still usable, one may transgress on the prohibition of Baal Tashchis (destroying useful products) and besides we maintain that an object that was already used for a mitzva, should continue to be used as much as possible.
Others opine that one should follow the tradition of the Beis Hamikdosh, where the Menorah was cleaned daily and new oil was used (Seder Hayom, Beis Halevy and others).
Horav Shlomo Miller’s Shlit’a opinion is that one should follow his family traditions.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit’a.