Freezing Vegetables: Mississippi State University Extension
For Quality Frozen Vegetables Get vegetables from the garden into the freezer as quickly as possible to preserve the quality of the food. Fresh, tender vegetables are best for freezing. The fresher the vegetables when frozen, the better your product.
First Steps: Begin most vegetables with washing. Wash thoroughly in cold water. Lift from water as grit settles to bottom of pan. Sort vegetables by size for heating and packing unless you plan to cut them into same-sized pieces. Peel, trim, and cut into pieces as directed for each vegetable. An important step in preparing vegetables for freezing is to heat or blanch them. Most vegetables, except green peppers, keep better quality in frozen storage if you heat them before packing. The reason to heat vegetables before freezing them is to slow or stop the action of enzymes. Until vegetables are ready to pick, enzymes help them grow and mature. After harvest, enzymes can cause loss of flavor and color. If vegetables are not adequately processed with heat, enzymes stay active during storage in the freezer. Vegetables may develop off flavor, discoloration, or toughen and become unappetizing in a few weeks. Heating also wilts or softens vegetables and makes them easier to pack. The type of vegetable and the size of the pieces determine the right heating time and temperature.