Can someone rip aluminum foil from a roll on shabbos, or is it best to pre rip it before shabbos? LECHATCHILA OR BIDIEVED
Aluminum foil should not be ripped on shabbos, not L’chatcila and not b’dieved, and it must be pre-cut before shabbos. The reason is because ripping the foil is korayah, and also it is making the foil usable and considered makeh b’patish.
Shulchan Aruch 340-13, M:B Ibid 41, Shmiras Shabbos Khichoso 9-26, Orchos Shabbos 19-125.