Uncooked asparagus stays fresh for three to four days in the refrigerator. Asparagus spears should be propped upright in an inch of water and covered with plastic.
Cooking fresh asparagus quickly in boiling water retains the color and its natural sweetness. Asparagus spears are thick when harvested early and become thinner throughout the season. The longer it takes to harvest, the more fibrous the stalks become. The rare white asparagus has a mild flavor and a softer texture than the green variety. Farmers cover these plants with soil which discourages the chlorophyll process that makes plants green. Purple asparagus is sweet and tender, but it reverts to green because pigment is lost through cooking.