yeah, its fine. I have done this method for about a year now. Ill put multiple cubes in the baster and sometimes leave them in the fridge for up to three days when I would get really lazy, with no ill effects. Only dont use foods with algae in them to do this with. the algae goes bad in a couple hours. or at least it dosnt look right to me. that said, I no longer do this because Im sure the food isnt as great two days later, but I still do it occasionally when lazy and only for over night.