Plunge lobsters headfirst into a 12-quart pot (see cooks’ note, below) of boiling salted water (
see Tips). Cook, covered, over high heat 4 minutes (for 1 1/4-lb lobster) to 5 minutes (for 1 1/2-lb lobster) from time they enter water. Transfer with tongs to a large colander to drain and cool. (Lobsters will not be fully cooked.) Return cooking water to a boil.