Parboiling is a method of partially cooking food in boiling water. When a recipe calls for parboiling, it is referring to the partial boiling of an ingredient just until it is soft but not cooked through. Parboiling is different from blanching in that after parboiling, you rinse the food under cold water, then cook it further or store it for later use; by contrast, blanching does not require a cold rinse or bath.
Uses for Parboiling
Most recipes call for parboiling to ensure that the ingredients that take longer to cook will be soft or completely done. Leaf.tv, for example, notes that parboiling reduces the total cooking time for many potato preparations. Parboiling potatoes make it easier "to achieve crispy edges with fully-cooked, fluffy interiors than if you started with raw potatoes," Leaf.tv adds. "Parboiling washes away some of the simple sugars present in the potato, resulting in a golden crust rather than a darker brown one."
Another instance where you might use parboiling is with a vegetable stir-fry that includes carrots. The carrots would likely not be cooked completely if you simply stir-fry them along with the other ingredients. When you parboil the carrots ahead of time, before tossing them into the stry-fry with the other ingredients, the orange vegetable is far more likely to be cooked through and tender after you finish cooking the dish.
Additionally, you can use parboiling to cook rice. Rice that has just been harvested is generally soaked in water and then parboiled, which helps crack the hard hulls. Parboiled rice is easier to process by hand and also has better nutritional value, as the process of parboiling drives nutrients like thiamin from the bran to the endosperm.
Parboiled rice also cooks more quickly and is less likely to spoil than raw rice.
How to Parboil
Parboiling is a simple process. First, fill a pot with enough water to cover the ingredient you intend to parboil. Bring the water to a boil while you prepare the ingredient -- the recipe may call for slices or cubes, or you may be parboiling the whole ingredient. While the water is boiling, place the food item in the water to cook. The length of cooking time will depend on the food item and the method of cooking you will be using later. Follow the recipe’s instructions for cooking time and desired texture. When you’ve reached the level of softness required, drain the boiled water and immediately run cold water over the food to stop the cooking process and maintain its color and texture. Set the food aside until you’re ready to use it.