I posted last week about making sweet potato baby food and how I stored it. Here is the process in pictures:

This silicone ice cube tray is food safe and BPA-free. Each cube is 1 oz. I froze the purée then moved the cubes to freezer bags. The idea is to grab a couple of cubes and defrost in the fridge, or even mix with other purée flavors to make the correctly-sized serving as he grows.

Not the most elegant solution, but easy to store and lasted about 5 days.