In the US, large globe artichokes are most frequently prepared for cooking by removing all but 5–10 mm or so of the stem, and (optionally) cutting away about a quarter of each scale with scissors. This removes the thorns on some varieties that can interfere with handling the leaves when eating. Then, the artichoke is boiled or steamed until tender. If boiling, salt can be added to the water, if desired. It may be preferable not to cover the pot while the artichokes are boiled, so that the acids will boil out into the air.
Covered, and particularly cut artichokes can turn brown due to the acids and chlorophyll oxidation. If not cooked immediately, placing them in water lightly acidulated with vinegar or lemon juice prevents the discoloration. Leaves are often removed and eaten one at a time, sometimes dipped in hollandaise, vinegar, butter, mayonnaise, aioli, lemon juice or other sauces. The remaining heart is then eaten, after removal of the inedible "choke".