I have to say at first i was wondering if this was a good idea becasue my baby wants his food instantly. Its not a good idea....its a great idea. we use them for his breast milk. All we do is put how many cubes we need in a bag and run it under warm water to melt the cube and bottle ready! It is much cheaper than buying the breast milk storage bags. I was going through 50 bags in just 5 day and at $10 a box that was getting expensive. The ice cube trays work great.