Nantucket, Mass. — A clambake feast is as old as an Indian legend and one of the truly aboriginal customs of New England. For the early colonists, it was a very practical method of cooking.
Later it became part of the social customs of many coastal towns and villages.
Today it is often left to professional bakemasters who ''put on'' the New England bakes for large families, churches, tourists, and other groups.
Some people prefer to cook clambake foods in a large kettle in an ordinary kitchen or on an outdoor grill or hibachi, since real clambakes are a lot of work and a way of eating that best suits large numbers of people.
But the results of the hard work are wonderful, with the native foods and the combination of smoke, steam, and salt producing a rather exotic blend of flavors - an aromatic taste of the sea.
The first requirement is a place with a view, such as a stretch of sandy beach on Nantucket Island off the coast of Massachusetts.
Add bushels of clams in the shell, dozens of ears of corn, buckets of greenish-black lobsters - these are the makings of an old-fashioned New England clambake.
Down a winding dirt road lined with blueberry junipers and rosa rugosa I went to just such a spot for a location shooting of the cooking segment of ''The Victory Garden,'' a PBS television series.
The host of the how-to gardening program, Bob Thomson, shows how to grow both vegetables and flowers, while Marion Morash, author of ''The Victory Garden Cookbook'' (Knopf), offers new methods for cooking the vegetables Mr. Thomson harvests.
On the beach ''Chef Marion'' was taking sweet corn from a huge crate, demonstrating how to remove the silk, fold the husks over the kernels again, and twist them closed for cooking.
The corn, about a hundred ears, was then placed in cold water for a thorough soaking.
The fire, started earlier, was now turning to hot coals, and benches made of long boards on sawhorses were set up for temporary tables.
''We wanted to do a true New Englands clambake - starting from scratch with the work divided among family and friends of all ages,'' said Chef Marion, who is also executive chef at Straight Wharf Restaurant on Nantucket.
Russell Morash, Marion's husband and producer-director of the show, wants everything to be done the old-fashioned way - no food wrapped in aluminum foil, nothing to spoil the basic Indian method of steaming by hot coals and seaweed.
Bob Thomson has made sure the corn is the very freshest, picked at its best and soon to be done to perfection.
''I've planned on food for 50,'' Chef Marion said. ''That means a lobster for each person, plus sweet corn fresh from the garden, potatoes, and lots of steamers, the small clams, best for this kind of cooking.
''Perhaps we'll add some fresh fish on the top. I'm sure the Indians and Pilgrims cooked whatever foods they had, all at once, while the fire was hot and the rockweed steaming.
''Every clambake has a bakemaster,'' she explained. ''Traditionally, the bakemaster doesn't do any work, he just tells others what to do.
''But my friends, Bud Enright and Dun Gifford, have grown up with clambakes, and they've been working since early morning.''
''We came early and picked up the biggest dry logs and driftwood for the fire ,'' Mr. Gifford said. ''And we collected rocks for the pit and bushels of rockweed.
''Rockweed is the best seaweed because it has these little bubbles or blisters with water inside which release moisture evenly,'' he continued, dipping into the water's edge for a handful.
''It doesn't compact tightly, and it gives good insulating space between the food and the hot rocks below.
''Years ago the colonists probably used old sailcloth for bake covers to keep the heat in. It's great if you have it, but otherwise you need a big canvas tarp just for this purpose.''
The embers were then raked away and a 4- to 6-inch layer of wet seaweed was strewn over the hot rocks.
Steamers and chicken were wrapped in cheesecloth bags - the old-fashioned way - and put on the rocks. Then the food was layered with more seaweed. Those items needing the longest cooking time go in first. The wet tarp covers all to seal in the heat.
At smaller bakes, Yankees often bring clam chowder already made or clam cakes to nibble on while the bake is cooking. At the Morashes' bake, there were beautiful, fresh mussels and Cotuit oysters to eat raw on the half shell or to heat to open on a small outdoor grill.
Most New Englanders agree on the basic foods that are truly authentic at a clambake, but additions of other foods have been made over the years.
There's always seafood, potatoes, and corn and usually some chicken. Additions include sweet potatoes, sausage, onions, corn bread or corn pudding, watermelon, and even hot dogs.
There are also adaptations of the fire-pit system. Bakes can be cooked in wash boilers, stovepipes with steel plates, wood and metal barrels, and large pots.
In some coastal towns you can buy a large pot with seafood already layered with seaweed, ready to take to the beach or to a home grill for cooking outdoors. Mussels were not cooked in the original Indian bakes, according to clambake aficionados. But Chris Heiser of the University of Rhode Island says his guests like them better than clams. He also adds eggs, cooking them in the unopened cardboard cartons.
Chris has had l7 years of preparing bakes for special groups and teaches a hands-on workshop called ''How to Do a Clambake'' every summer at the university.
Most bakemasters agree that the best way to determine how long the clambake should ''cook'' is determined by placing a potato on top of the bake or at a spot where it will be easy to remove without losing any heat. After the bake has been sealed and has cooked for an hour, the potato is brought out and tested. If done, the whole bake is ready. If it needs another hour or half hour, the bake cooks on.
''Breaking the bake'' is the phrase that brings everyone running. It means the food is finally ready and the aromas and the whoosh of steam when the big tarp is lifted are almost as exciting as eating the whole meal.
Some families use clambakes as an occasion for family reunions. One reunion in Carver, Mass., will draw 800 to 1,000 people this year from as far away as California and Arizona.
''It was started by Aunt Jane Barrows, with a family gathering and clam chowder in 1964,'' Marjorie Mosher said.
''But it grew over the years and now we have a doll carriage and bicycle parade, a band concert, a five-mile road race, and a pie-baking contest.''
Clambakes are not always limited to the seashore. Jim Lumsden, a bakemaster for many years and also a high school teacher in Freeport, Maine, has put on bakes at the White House for three presidents and has gone as far as Hawaii with his seafood dinners.
He cooks his whole bake in 45 minutes using a steel plate on cement blocks and loads of rockweed. Most bakemasters are quick to encourage others who want to have clambakes for small groups. They often give the same advice:
Try it. But don't make a clambake into something monumental. Make it simple, make it old-fashioned - but make it.
The ''Victory Garden'' program with Marion Morash's Nantucket clambake is scheduled to be aired on PBS next Tuesday, but check local listing for times and dates that may vary.