Can a person squeeze water from a can of tuna on Shabbos/Yomtov? If yes, what is the most recommended or best way Halchically?
My assumption is heat you are squeezing the water out of he can because the tuna is tastier when it has less water content. As far as sechita is concerned it would be permitted, the reason being that we are allowed to squeeze a food of its absorbed liquids (kevashikm ushelakos) if the reason for squeezing it is to improve the actual food. The main issue however is borer, because we have a mixture of unwanted water and wanted tuna in the can. According to some poskim it is permitted to pour off the excess water, until the flow of water starts to drip. Others however argue that it would still be borer to pour the liquid out. Therefore the best way to do it would be to empty the whole can into a plate, then take out the tuna and squeeze it out.
It is needless to say that the best option is to squeeze the tuna out before shabbos, and to avoid the whole issue.
Shulchan Aruch O:CH 320- 6, Nishmas Shabbos 4-207, Shmiras Shabbos Khilchoso 3-20, Hilchos Shabbos B’shabbos 9-46, The Shabbos Kitchen pg. 122, The 39 Melachos pg. 342. Orchos Shabbos 3-42 Halachos os Shabbos ( R’ Eider zt”l) Borer ftnt. 245.