Can someone put away leftover Cholent or other food on Shabbos day (not necessarily Friday night) in the refrigerator so that it does not spoil? This leftover food will obviously be used for after Shabbos. Putting the leftovers into containers, and then placed in the refrigerator. If the food is left without refrigeration it sours. Is there a way it can be done Halachcally correct?
It is permitted to put leftover food after the Shabbos day meal in the refrigerator and it is not an issue of hachana for the weekdays. There are a few reasons given by the poskim. Some say like what you mentioned, that if it is done so that the food should spoil it is permitted. Others say that since it is the norm to return the food to the fridge after the meal, it isn’t considered hachana.
Tehila L’dovid O:CH 121-6 D:H Umdivrei, Be’er Moshe 8-202, Minchas Shlomo 2 siman 36-6, Shmiras Shabbos Khilchoso 28-89, Orchos Shabbos 22-163 &176.