At the fish market, select one lively, tail-flipping, claw-raising lobster per person.
You pick up a lobster by grasping its back, behind the head. If it droops when picked up, forget it and come back another day; it’s not fresh.
Take the lobsters home in a container that allows lots of breathing space and keeps them cool. Even though they’re aquatic, they can live in the air for several hours if kept cool and moist.
Select a covered, deep stockpot big enough to contain the lobsters completely immersed in water. (Use 3 quarts of water per 1½ to 2 pounds of lobster, taking into account that the pot should be filled no more than three-quarters full.)
As the moment of truth draws near, add 1/3 cup kosher salt for each gallon of water (to create mock seawater) and bring it to a rolling boil.
Pick up the lobsters one at a time and plunge them in head first. Cover, return to the boil, then reduce the heat and simmer. A 1¼-pound lobster will take about 11 minutes; 1 pound, about 8 minutes; 2 pounds, about 15 minutes. Do not overcook, or the delicate meat will toughen.
With tongs, remove the lobster from the water, being careful not to let it slip back into the water and splash. Place on a paper-or cloth-covered counter.
Drain the excess water from the lobster by punching a small hole between the eyes with the tip of a small knife. Prop each lobster in a pot or in the sink with its head down so that the liquids drain from the carcass. This makes less of a mess when the lobster is opened.
Whisk to the table and serve with melted butter and lemon wedges.