Buying directly from the fishing companies ensures fast and fresh delivery since the lobster are often sent by air and this is often the only option if you don't have a local market that offers live seafood.
If you happen to live near a market that sells live seafood, take the opportunity to pick out your own lobster and ask the fishmonger his or her recommendation for lobster recipes. Guaranteed, you'll get a good idea of how to serve fresh lobster and the store's staff will also be able to judge whether you're purchasing enough lobster to feed guests without overbuying.
When choosing lobster it helps to understand industry standard sizes.
Culls are 1 lb. and under. They are often missing a claw or have other shell damage, so are not perfect for presentation, but are a good value if you will be removing the meat to serve cold in a salad or lightly reheated in a cream sauce over linguini.
Chicken sized lobsters are 1 to 1.5 lb. and Regular sized lobsters vary between 1.5 lb. to over 3.5 lb.
Despite being sold by the pound, a single 1-lb. lobster will weigh approximately 14 oz. when cooked. It will yield 3.5 to 4 oz. of meat when the shell is removed. (Don't think of the 10 oz. of shell as waste because you can use it to flavor soup bases.)
If you are serving lobster as the main course, buy 2 to 2.5 lb. of lobster per person, allowing each guest 8 to 10 oz. of meat.
If you will use the lobster meat in an appetizer or salad, buy 1 to 1.5 lb. of lobster per person. Appetizer recipes often call for 3.5 oz. of shredded meat from a 1 lb. lobster, except when a single lobster is split and served as a cold appetizer, then purchase a single 1.5 lb. lobster for every 2 guests.
Green salads are often topped with 4.5 oz. of whole lobster meat from the claw or tail. However, traditional salad filling for lobster rolls often uses slightly less lobster per serving because the filling is split between hefty rolls and sometimes includes vegetables.
For surf and turf dinners where lobster is paired with a steak such as filet mignon or New York strip buy 1 lb. of lobster per person minimum.
Frozen Lobster Tails
With surf and turf presentations you can also opt to buy frozen lobster tails, rather than live whole lobsters. Buying frozen lobster means you will cut your preparation and cooking time because lobster tails are usually cooked before being frozen.
Frozen lobster tails are always from clawless spiny lobsters (rock lobsters) harvested in a wide range from warm tropical waters to colder northern waters. Buy cold-water tails if possible because they tend to be better than warm-water tails.
Thaw the lobster before you start cooking dinner then throw the lobster tails on the grill or under a broiler a few minutes before your steaks are done to ensure everything comes off the heat at the same time.
When paired with an 8 oz. steak, plan on serving one 8 oz. tail per person. If you are serving lobster tail as the main course, plan on two 5- to 6-oz. tails per person
Canned Atlantic Lobster Meat
If you are preparing appetizers or soup, consider using canned lobster meat rather than fresh lobster. Canned lobster is packed in 12-oz. cans and typically includes 2 small tails, some claws and bits of shredded meat.
One 12 oz. can will have 9 oz. of lobster meat which is more than enough for most appetizer recipes serving 4 to 6 people.