Is one allowed to open a soda can on Shabbat? What about a bottle?
Rabbi Shlomo Zalman Auerbach in His Book Minchat Shlomo (2; 32) defines three different cases. A soda can: one is allowed to open on Shabbat. A plastic bottle lid, (coke style): one is allowed to open on Shabbat. (Some strict opinions do exist) A metal lid, (like in some wine bottles): one should open before Shabbat since he is creating a vessel on Shabbat. (lenient opinions do exist)