Under running tap water, gently and thoroughly wash the fresh cabbages then dry them.

Cut your cabbages into thin wedges or use a grater to shred them.

Divide the sliced or shredded cabbages into separate freezer bags or airtight containers.

If you happen to use freezer bags instead of airtight containers, make sure to remove the air from the bags. To do this, put a straw in a corner of the bag and seal the bag around it. Submerge the bag into tap water and press out the air through the straw. Then take the straw out and seal the bag completely.

Label each freezer bag or airtight container with its content and date. 

Freeze the bags or containers in your freezer.