Add 15 oz of washed and dried spinach to a blender with ¼ cup of water and blend into a puree. Pour puree into an ice cube tray and freeze for at least 3 hours. Remove the ice cubes and pack them into freezer safe bags!
Freezing Spinach Leaves (No Blanching)
Wash and dry spinach thoroughly. Measure and pack them into a freezer safe bag. Close the bag almost all the way, and then remove any excess air, and then seal the bag. Place in the freezer.
Freezing Spinach Leaves (Blanching)
Bring a large pot of water to boil. Add the spinach to the water once it's boiling and submerge for around 1-2 minutes. Remove and transfer to an ice bath for 3 to 4 minutes and allow it to cool down complete. Squeeze the excess water out of the spinach thoroughly. Measure out the spinach in cups and then transfer to a freezer safe bag.
Notes
Blanched spinach leaves and spinach puree / smoothie bombs tend to last for about 3 to 4 months. If you're freezing spinach without blanching, I suggest using it up within a month at most!
Some people think that cooking strips the spinach of its nutrients - but this isn't fully true! Check the post for details. Blanching helps preserve the taste and color of spinach so if you care about that, blanch it first!