Vegetables do not have to be blanched before freezing, but it is recommended to preserve color, flavor and nutrient values. Blanching sets the color and flavor, kills microorganisms and stops enzymatic action that can degrade the vegetables' quality during storage. Hot and sweet peppers, onions and raw tomatoes do not need to be blanched before freezing.
Vegetables should be washed, cut and placed in 1 gallon of boiling water per pound of vegetables. After the water comes back to a boil, put a lid on the pot and count blanching time once the water comes back to a boil. Once the vegetables reach a bright color, remove them from the water and place them in ice water to stop the cooking process.