Fill the pot salted water and bring it to a boil.
Put the strainer in the sink.
Fill the bowl with equal parts of cold water and ice cubes. Keep some ice cubes in the freezer for later.
Drop the kale leaves into the boiling water with the tongs. Don't overcrowd the pot. Boil the leaves for 2 minutes.
Move the kale leaves from the pot to the bowl of ice water with the slotted spoon. Rest the kale leaves in the ice water for 2 minutes.
Let the water come back to a boil. Drop the kale stems into the boiling water with the tongs. Don't overcrowd the pot. Boil the leaves for 3 minutes.
Use the slotted spoon to move the leaves from the ice water to the strainer. Shake off as much water as you can.
Add more ice cubes to the cold water. Move the kale stems from the pot to the bowl of ice water with the slotted spoon. Rest the kale stems in the ice water for 2 minutes.
Place a towel on a flat surface and lay the kale leaves on the towel. Pat the kale dry with another clean cloth.
Use the slotted spoon to transfer the stems from the ice water to the strainer. Shake off as much water as you can. Add the stems to the towel and pat them dry with a towel, too.
Let the kale air dry for at least 30 minutes to prevent freezer burn.
Pack the blanched leaves into a freezer bag.
Place the kale stems in a separate 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 kale. Slide the bag down the straw as you inhale, and quickly seal the bag while you remove the straw.
Write today's date and the amount of kale on each bag. Put the bags in the freezer.