How To Freeze Fresh Spinach - Method 2: Freezing Spinach Without Blanching
If you freeze raw spinach, you need to use it within 6 months. It won't keep as long in the freezer and will lose its flavor.
Pack the clean spinach leaves into a freezer bag.
Press the air out of the freezer bags and seal them.
Straw "vacuum seal" trick (optional): Slide a straw into the bag and suck out the air so the bag "shrinks" around the spinach. Slide the bag down the straw as you inhale, and quickly seal the bag while you remove the straw.
Write today's date on a freezer label, stick it to the bag, and place the bag in the back of your freezer.