Blanching vegetables, before freezing or canning, helps retain the flavor, color and texture. Blanching is the process of scalding vegetables in boiling water, steam or microwaving. It cleanses the surface, kills organisms, and helps stop the loss of vitamins. It also wilts and softens vegetables, making them easier for packing when canning.
However, the time it takes to blanch vegetables is very important. Under-blanching vegetables can cause enzymes on the vegetables to stimulate and grow. Over-blanching vegetables causes loss of flavor, color, vitamins and minerals.
Water Blanching Vegetables
The best way to blanch vegetables is by using boiling water. You can use a blancher or a stock pot with a wire basket and lid. It is important to make sure that you use enough water when blanching. A good rule of thumb is to use one gallon of water per pound of vegetables. Make sure that you do not mix your vegetables before blanching either. The water should return to boiling within one minute, or you’ll have too many vegetables for the amount of boiling water. Use a digital timer to make sure that your vegetables are blanching for the right amount of time. Keep heat high during the cooking time given in the directions for the vegetable you are freezing or canning.
Once blanching is complete, vegetables need to be cooled immediately to stop the cooking process. Plunge the basket of vegetables immediately into a large quantity of cold water, 60ºF or below. Vegetables need to be cooled the same time as blanching.
|Asparagus||Small Stalk: 2 Minutes
Medium Stalk: 3 Minutes
Large Stalk: 4 Minutes
|Snap Beans, Green Beans, Wax Beans||3 Minutes|
|Lima Beans, Butter Beans, Pinto Beans||Small Batch: 2 Minutes
Medium Batch: 3 Minutes
Large Batch: 4 Minutes
|Broccoli||1-1/2" Flowerets: 3 Minutes
|Carrots||Small Batch: 5 Minutes
Diced, Sliced or Lengthwise: 2 Minutes
|Corn-on-the-cob||Small Ears: 7 Minutes
Medium Ears: 9 Minutes
Large Ears: 11 Minutes
|Okra||Small Pods: 3 Minutes
Large Pods: 4 Minutes
|Peppers||Halves: 3 Minutes
Strips or Rings: 2 Minutes
|Summer Squash||3 Minutes|
Steam Blanching Vegetables
Steam blanching vegetables is recommended for a few vegetables such as broccoli, pumpkin, sweet potatoes and winter squash. However, steam blanching takes about 1-1/2 times longer than water blanching vegetables.
To steam, use a stock pot with a tight lid and a basket that holds the food at least three inches above the bottom of the pot. An inch or two of water in the pot is all that is needed and bring the water to a boil.
Put the vegetables in the basket in a single layer so that steam reaches all parts quickly. Cover the pot and keep heat high. Start counting steaming time as soon as the lid is on.
Cool steamed vegetables with the same process as water boiling vegetables.
|Asparagus||Small Stalk: 3 Minutes
Medium Stalk: 4-1/2 Minutes
Large Stalk: 6 Minutes
|Snap Beans, Green Beans, Wax Beans||4-1/2 Minutes|
|Lima Beans, Butter Beans, Pinto Beans||Small Batch: 3 Minutes
Medium Batch: 4-1/2 Minutes
Large Batch: 6 Minutes
|Broccoli||1-1/2" Flowerets: 4-1/2 Minutes|
|Carrots||Small Batch: 7-1/2 Minutes
Diced, Sliced or Lengthwise: 3 Minutes
|Corn-on-the-cob||Small Ears: 10-1/2 Minutes
Medium Ears: 13-1/2 Minutes
Large Ears: 16-1/2 Minutes
|Okra||Small Pods: 4-1/2 Minutes
Large Pods: 6 Minutes
|Peppers||Halves: 4-1/2 Minutes
Strips or Rings: 3 Minutes
Microwave Blanching Vegetables
Blanching vegetables in a microwave may not be effective as boiling or steaming. Flavors could change and there can be a loss of texture and color when microwaving. It does not save time and energy as the former and is best done in small batches.