Winter at Penn State means icicles and ice cream.

While some people head south to avoid the freezing temperatures, more than 100 students from around the world came to State College this month for the frozen dessert.

These students are here for the Ice Cream Short Course, an annual class run by the College of Agricultural Science that continues through Thursday.

"Penn State is not unknown in the dairy industry. It is quite famous, actually," said Wernick Van Buuren, who hails from Holland but is on his way to Guam to work at a dairy run by a Chinese company.

Students such as Van Buuren will attend the nine-day, $1,005 course to develop an intimate knowledge of frozen goodies and the machines that make them.

Penn State began offering the Short Course in 1892 — making it the oldest such class in the world.

Bob Roberts, an associate professor of food science, is in his third year of teaching the course.

"In some cases, I think it's viewed as corporate training," Roberts said. "In some cases, I think it's viewed as a corporate training perk."

Roberts said the students — representing some of the largest ice cream companies and some mom-and-pop shops — come here to learn and have a good time.

"You have people in there who, from a marketing perspective, would slit each others throats," Roberts said. He shrugged. "Nah, not here. They're buddies."

In labs last week, students tasted different vanilla ice creams, including various commercial brands and samples that showed different manufacturing methods.

Some of the variables in ice cream include the amount of fat, the type of sweetener and the overrun -- basically, how much air is whipped in.

Slight variations in ingredients, temperature or equipment can produce subtle differences. That's part of the reason that the University Creamery is held in sacred regard for consistently producing top-notch ice cream.

During a lab last week, students donned the dreaded hairnets (and the even-more-dreaded beardnets) and ventured into the basement room in Borland Lab where the Creamery produces its ice cream.

Phil Keeney, a legendary ice cream instructor who retired from Penn State in 1985, was there to help out, watching quietly from behind the rows of industrial mixers and freezers.

"People involved with ice cream are usually pretty good spirits, and smile," Keeney said.

Thirty years of teaching dairy science at Penn State left Keeney with an unusual talent: He can tell the exact temperature of fresh ice cream just by looking at it.

He was a little off the mark Thursday. Of three sample batches, he was only able to guess to the exact tenth of a degree once.

"He's been pretty close today, but he's missed a few," said Maria Ruhlman (senior-food science), an assistant in the lab, sounding slightly disappointed.

With Creamery equipment, Roberts showed how different kinds of freezers produce crystals of different sizes, affecting the consistency of the ice cream.

Freezing was a key theme last week, both in and out of the class.

"We walked downtown on Monday night when it was, like, one below," said Leisha Hartis, who works for an Atlanta company that makes stabilizer, an ice cream ingredient. "We can handle it. We're just here to learn about ice cream."