Q. See question above; Can one then be lenient to make ice cubes on Shabbat?
A. Dovev Meisharim (55) rules that changing water into ice is forbidden on Shabbos. and even if the water was placed in the freezer before Shabbos began, if it freezes on Shabbos, the ice would still be forbidden because of molid and would be Muktza.
However, Chelkas Yaakov (O. H. 128) and many other Poskim disagree on both points. Not only is ice that solidified on Shabbos not muktza, but there may not be any prohibition to make ice.
The Chelkas Yaakov recommends not making ice on Shabbos unless there is a need.See also Shevet Ha’Levi, (1: 119). and Halichos Olam, (4, p. 93).
Horav Shlomo Miller’s Shlit’a opinion is similar.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch Ehrentreu Shlit’a