When fresh asparagus is briefly boiled in water then promptly cooled it has been blanched. A quick way to barely cook asparagus, blanching allows the vegetable to tenderize while maintaining its crispy texture. Blanched asparagus is used for side dishes or in main courses.
Although asparagus stalks are usually blanched whole, they may be cut before or after the cooking process. Using fresh asparagus, in good condition, is always advisable. Good quality asparagus will have straight stalks and tight tops that are tinged slightly purple. Normally this vegetable is green, but white and purple asparagus is also available.
Before the asparagus is cooked, the hard ends must be removed. The hardness of the ends varies with the thickness of the stalks, so for thicker stalks, bending the last half of each stalk until it breaks is the simplest way of ensuring the entire tough end has been removed. For thinner stalks, trimming the ends with a knife should be sufficient.
To blanch the asparagus, a pot is filled with water and boiled. Usually, salt is added to the water, but it may be omitted. While the water heats, an ice bath is prepared. A bowl, large enough to hold the asparagus, is filled with cold water and usually placed in a larger bowl filled with ice. The ice ensures the water stays extremely cold while it is being used.
Once the water is boiling, the asparagus can be placed into the pot. Cooking time varies based on both the thickness of the stalks and the cook's preference. The vegetables may boil between 30 seconds and five minutes before they are removed and placed into the ice bath. The ice bath immediately stops the cooking process. Properly blanched asparagus should be a bright green color.
The asparagus is allowed to cool in the bath before the stalks are drained. Blanched asparagus should not be confused with boiled asparagus, which more thoroughly cooks the stalks and does not use a water bath. Both boiled and blanched asparagus may reduce the flavor of the vegetable, however, giving it a slightly watery taste.
Blanched asparagus can be served plain or with hollandaise sauce. Tossing the stalks with lemon and olive oil is also an option. Additionally, almonds and shallots may be added to the dish for increased flavor. Blanched asparagus can be placed in dishes like stir fry directly before the dish is finished as well.