To freeze raw asparagus, wash, trim, remove scales, blanch and drain the spears, before packing into containers. Cut the spears into even lengths to fit the freezer containers, such as plastic bags, containers or jars. Blanch for two to four minutes, depending on size.
Remove from heat, cool, drain and package the spears. You do not need to leave head space, simply seal the containers and put them in the freezer. Alternatively, choose to freeze spears individually before packaging them to avoid freezing them in a single lump. As asparagus is high in water content, the water in the spears turns into ice crystals that break down the plant cells; therefore, the defrosted spears are softer than other types of frozen vegetables.