Some of the students averted their eyes as the turkey flapped about for a minute or so. After Clemmer dipped the turkey in hot water to loosen the feathers, students rushed to pluck the bird.
Clemmer told his students to remember the lesson when they eat chicken nuggets at a fast-food restaurant.
In an interview later, Clemmer said, "I just want them to have a realistic view of what it's all about."
Clemmer's students have re-enacted Thanksgiving ever since he started teaching at the Brown's Mill School 31 years ago. At first, students erected teepees and ate in the classroom. Later, the events were held at the environmental center.
The re-enactments are featured in current issues of Child Life magazine and Scholastic News.
Clemmer said the hands-on activity helps students get interested in learning about history.
And the food's not bad, either.
Students feasted on Indian corn bread, fresh pumpkin pie, vegetable stew, Jerusalem artichokes, fresh-pressed cider and sweet, spit-roasted turkey. The turkey students feasted on was not the same one that was killed during the demonstration.
The food didn't come ready-made from a supermarket. Instead, the students worked with each other and with parents to grind the corn, mix ingredients, crush the apples, prepare the vegetables, turn the turkey spit and decorate the tables.
"It turns out to be one of the best meals they've ever had, and they did it," Clemmer said.
Students and parents were enthusiastic about the day, although a few students said they could have done without the turkey demonstration.
"The turkey was pretty," said Brittnay Snyder, 10. "We felt bad for it. But it was neat because I'd never seen a turkey killed before. It was different."
Randy Rose, father of Rebecca, 10, and former Clemmer student Brad, 15, said it was his second time coming to the re-enactment. He said the first time he came just for the food.
"It's fantastic. It's hard to find something like this," he said. "It really makes kids appreciate what we have today compared to what they had then. And the camaraderie is fantastic. You don't see anybody arguing and bickering. I'd like to see more schools do this sort of thing."
The students, who have been studying the pilgrims for weeks in class and had to write reports, said they had learned of the sacrifices they had made.
"The pilgrims had to work hard to get here," said Dustin Mowen, 10. "They were in search of religious freedom ... We should pray for a good while for what the pilgrims did. We should celebrate that we have a good freedom."
Others had more immediate thoughts on their minds. "My favorite part about this is we can wear hats in the building," said Tony Jansen, 11.
Jennifer Rozansky, 11, went straight to the source for her costume. Her family got in touch with Plymouth Plantation, which sent her period clothing.
Dacia Thrush, 11, said she's been looking forward to the day since hearing about it from friends over the summer. She made much of her costume.
"My mother thought it would be a good experience for me," she said.
Before the meal, students sang a pilgrim hymn and said voluntary prayers, thanking God, their families, their friends and their teacher.
As for Clemmer, he said he enjoys the re-enactments so much he may come back and do them after he retires.