The two most common ways to cook lobsters are steaming and boiling.

Steaming lobster
Pour 2 inches of seawater into a pot large enough to comfortably hold the lobsters. Some cooks also place a steaming rack large enough to hold the lobsters above the water, in the bottom. Bring water to a rolling boil over high heat. Place lobsters in the pot, cover tightly, return to a boil as quickly as possible and start counting the time.

Steam a lobster for 13 minutes per pound, for the first pound. Add 3 minutes per pound for each additional pound thereafter. For example, a 2-pound lobster should steam for 16 minutes and a 1 ½-pound lobster should steam for 14½ minutes.

Boiling lobster
The number of lobsters to be boiled determines the minimum kettle size. The water should fill the pot one-half to not more than two-thirds full. Bring water to a rolling boil over high heat. Place lobsters head first into the pot, completely submerging them.

Cover the pot tightly and return to a boil as quickly as possible. When water boils, begin counting the time. Regulate the heat to prevent water from boiling over, but be sure to keep the liquid boiling throughout the cooking time.

Boil a lobster for 10 minutes per pound, for the first pound. Add 3 minutes per pound for each additional pound thereafter. For example, a 2-pound lobster should boil for l3 minutes and a 1 ½-pound lobster should boil for 1l ½ minutes.

Note: These times are for hard shell lobsters; if cooking new shell lobsters, reduce boiling or steaming time by three minutes. When the antennae pull out easily, the lobsters are done.

From: Cooking Maine Lobster, there’s more than one way...
Maine Lobster Promotion Council. 1998. 54 pp.