Question: Can one put water and ice pops in the freezer on Friday night so that they can have ice cubes and ice pops on Shabbos?
Answer: R’ Chaim Palaji (Lev Chaim 2:192) writes that one can’t make ice on Shabbos. He compares it to producing cheese from milk which is forbidden as it is a form of boneh, building a new substance. R’ Dov Berish Weidenfeld (Dovev Mesharim 1:55) writes that it is forbidden because of nolad, the prohibition against using things that were born on Shabbos.
R’ Ovadia Yosef (Halichos Olam 4:p93; Yechave Daas 1:30) allowed one to freeze water on Shabbos, arguing that creating ice is different from cheese as it would quickly change back to water if left out. R’ Shlomo Zalman Auerbach (quoted in Shemiras Shabbos Kehilchasa 10:n14) held that there is no issur in creating ice on Shabbos. As the Shulchan Aruch (OC 320:10) allows one to break ice in a jug on Shabbos, we’re clearly not worried about nolad. Thus, R’ Shmuel Wosner (Shevet Halevi 3:55) and R’ Yehoshua Neuwirth (Shemiras Shabbos Kehilchasa 10:4) write that while one should ideally make the ice before Shabbos, in case of great need (e.g. one has guests coming), one may do so. Likewise, R’ Yitzchok Yaakov Weiss (Minchas Yitzchok 8:24) writes that one can put food in the freezer on Shabbos to prevent it from getting ruined.Certainly, one can only make ice on Shabbos for that day, and not for after Shabbos.