The newly crowned state dairy princess got what could only be called a chilly reception on the opening day of the Minnesota State Fair this year.

That came as no surprise to the new royal, Rebekah Dammann, 19, of Lester Prairie, Minn. It was precisely the same reception that 40 state dairy princesses before her had received -- namely 38 degrees Fahrenheit. And Ms. Dammann was actually looking forward to it.

So running on two hours of sleep, the 52nd Princess Kay of the Milky Way donned several layers of clothing on Thursday and stepped into a custom-made refrigerator with glass walls to have her likeness sculptured in a 90-pound block of Grade A salted butter as fairgoers -- ice cream cones in hand -- looked on.

Ah, such is the life of an icon. And for Minnesotans, Princess Kay's status as the dairy industry's good-will ambassador, is ''the equivalent of Queen Elizabeth's role as the physical embodiment of the British Empire,'' as The St. Paul Pioneer Press put it.

Helping raise her to that level is the rite of late summer that has come to be known fondly as ''the carving of the butterhead.'' Like the Polar Bears' swim off Coney Island on New Year's Day, the sculpturing of Princess Kay and her court is the kind of event for which it may be fruitless to reason why.

Even the artist who has created the sculptures for more than three decades, Linda Christensen, acknowledges, ''It's just so weird.''

Unlike other tiara-wearing role models, Princess Kay does not select a cause to advocate. Her reason for being is the dairy industry. She visits schools and makes other appearances, reminding people to eat three servings a day of milk, cheese, ice cream or yogurt.

The first state dairy princess, Eleanor Maley, was crowned on Aug. 28, 1954, after the official title Princess Kay of the Milky Way was chosen from 10,000 entries in a statewide contest, according to the Midwest Dairy Association, based in St. Paul.

In 1965, the idea of using butter sculpture to highlight Minnesota's position as the top butter-producing state was hatched and Don Schule, who taught art at the University of Minnesota, auditioned for the job by carving the 1964 Princess Kay, Karen Bracken, using the Land O'Lakes creamery's freezer as his studio. Later that summer, Mr. Schule sculptured the 1965 princess, Mary Ann Titrud, in the specially constructed butter booth, with revolving floor, that is still used today at the fairgrounds.

Ms. Christensen saw Mr. Schule in the butter booth on a particularly hot, humid day at the fair one year. ''I thought to myself, 'I want to be in there,''' she said, admitting that she had been thinking more about air-conditioning than art. Now from the other side of the glass, she said, she sees the same expression on some faces. ''They have murder in their eyes,'' she said with a laugh.

After graduating from the Minneapolis College of Art and Design in 1972, Ms. Christensen got the job by doing a partial bust of the daughter of a dairy association official. After a couple of hours, when the likeness was just barely taking form, she was told: ''That's fine. You'll be able to do this.'' So she completed her first butter sculpture on the fair's opening day with an audience. ''I didn't know if I could do it,'' said Ms. Christensen, who now lives in Southern California.

Ms. Dammann was chosen in a competition that narrowed a field of about 80 county dairy princesses to 12 in May. Each was either a worker on a dairy farm or the daughter of a dairy farm owner or worker. Final judging -- on appearance, communication skills, knowledge of the dairy industry, personality and enthusiasm -- took place on Tuesday. The next night at the fairgrounds bandshell here, the 2004 Princess Kay, Tina Rettmann, waved a tiara over the heads of the three top scorers before placing it on Ms. Dammann.

''I just have a passion for dairy farming,'' said Ms. Dammann, who decided to forgo college to work full time on her aunt and uncle's farm, where she feeds calves, helps with milking and cleans stalls.

On Thursday, there was no snoozing in the butter booth. Ms. Dammann, who woke at 4 a.m. (a half-hour later than usual) had already had several broadcast interviews, when she entered the booth at 9 a.m. She smiled and waved her mittened hand at family, friends and passers-by. Television and newspaper photographers waited for their five minutes in the booth -- the time limited so the temperature would not rise.

Princess Kay's parents, Mary Jo and Dan Dammann, watched proudly, handing out official Princess Kay trading cards and sipping malts.

Throughout, the sculptor stayed focused, using seven tools, including wires and knives, and even her fingers. One day is barely enough time to complete a sculpture, she said, and with breaks for warming up, lunch and a parade, every minute is precious. And she repeats the process for each of the 11 other finalists.

All the butter scraps were collected in five-gallon plastic pails to be given to the princess. When the fair ends on Sept. 5, Ms. Dammann's butterhead will be packed in a box and sent home with her. A friend of her family has offered to provide freezer space.

Photos: The butterhead of Ms. Dammann, a work in progress in a booth at 38 degrees Fahrenheit.; Rebekah Dammann, newly crowned Princess Kay of the Milky Way, bundled up for Linda Christensen, the state fair's butter sculptor for 30 years. (Photographs by Ingrid Young for The New York Times)