Robert Elder, left, and Jessica Finnearty use a colorful tube of Jell-O to symbolize different ages of rock layers during a biostratigraphy lesson during the Jell-O Nation event Sunday at the Kansas University Natural History Museum, put on by KU graduate students. Biostratigraphy is the idea of using fossils to determine the age of rock layers.

Long after the Jell-O molds had set and the students brought the long-lost recipes back to life, it became clear why some flavors never worked in the first place.

“With some, it’s not so mysterious,” Kansas University student Samantha Harper said, looking down at the rather disliked apple Jell-O flavor.

Harper and the rest of her class spent Sunday trying to explain the history of, and science behind, gelatin and Jell-O products at the KU Natural History Museum.

Spread throughout two floors of the museum, students in the public education class from the museum studies graduate program displayed everything from old television shows sponsored by Jell-O to the samples of discontinued Jell-O flavors sitting in front of Harper and her classmates.

“We went through a lot of different ideas, but we wanted something the kids would enjoy,” graduate student Martina Smith said. “What’s more fun than Jell-O?”

McKenzie Blaylock, 7, tries out her new Jell-O creation with her friend Garrett Hockersmith, 4, in the jelloangelo room of the Jell-O Nation at the Kansas University Natural History Museum Sunday afternoon. Once a Jell-O color was created, the creator could name it. The Museum Studies Program staged the event, which was open from 1 p.m. to 4 p.m.

Well : how about Jell-O flavors that no longer exist – like cola and pineapple-grapefruit?

The flavors were not, of course, the original recipes. Harper said Jell-O – or, more likely Kraft Foods, its parent company – keeps those a secret in case it ever wants to give former flavors another shot.

Instead, the KU students mixed plain, flavorless gelatin with what they thought would produce the flavors – such as apple juice for the “apple” flavor.

People signed their name under which flavor they liked the best. Late in the day, “apple” had only a handful of signatures.

In all, the class project took about a month and a half to complete, and about 75 people – including many children – toured the Jell-O exhibits and interactive stations Sunday.