Jerry Hancock, founder and owner of Sub Zero Ice Cream, demonstrates how liquid nitrogen creates higher pressure inside a water bottle, causing the water to shoot out into the audience of eighth grade students at Timberline Middle School. Photo by Karissa Neely

by Karissa Neely – Daily Herald Correspondent

The audience of eighth-grade students expected to get rather wet in the Timberline Middle School auditorium, but even with water shooting out and up and over, it missed them — mostly.

Timberline eighth-grade science classes were treated to some hands-on science by founder and owner of Sub Zero Ice Cream Jerry Hancock. And even when they didn’t want to be hands on, he encouraged them to anyway.

Sub Zero Ice Cream is a store steeped in chemistry, and rightly so, since Hancock graduated from college with a degree in chemistry. Hancock came up with the idea that he could make ice cream even creamier by instantly freezing the cream and flavors with liquid nitrogen. And with the success of his ever-growing franchise, started in one little store in Orem, and branching across Utah and the West, many would agree.

What makes his ice cream different from any other ice cream store? One word, he’ll say: customization. His ice cream is fully customizable from the very beginning.

“Science is about observing things,” Hancock taught the Timberline students. “And in business, if you’re looking for a new product, then you find out what people like, and you do it better. Or you find out what they don’t like and solve that problem. That’s where we come in, with customization.”

He said in other ice cream stores, you can add flavors or toppings, but you have to pick from a base set of ice cream flavors they have there. In his stores, you start with the cream. You can choose how much fat content you want in it, you can choose what texture it has, you can choose to start with yogurt instead, you can even choose a non-dairy cream. And then you build from there. You create your custom flavor from the very beginning, and then it is frozen into ice cream as you watch.

Why is that better? His explanation had to do with water.

He explained to the classes that as the ice cream freezes the water molecules bond. As the water freezes, the ice crystals grow and expand. But the faster the ice cream freezes, the smaller those water molecules grow, and the creamier the taste.

“When you freeze it almost instantaneously, you actually create more water crystals but they are much smaller, so the ice cream is so much more creamy,” Hancock said.

Essential to this process is the liquid nitrogen. Many of the students confused liquid nitrogen with dry ice. They are two completely different substances, and Hancock proved it to them, by allowing them to touch it. He explained that they are able to put their hands in the bowl he held, because the nitrogen is so cold, sitting at minus 321 degrees Fahrenheit, but still a liquid, so it formed a vapor barrier between their hands and the actual liquid.

“Dry ice is not nitrogen. Dry ice is not a liquid, it is solid, and because it is solid, it does not create a vapor barrier. That’s why you will be hurt if you touch it,” Hancock said, as he poured some of the liquid nitrogen out onto the carpet floor.

The nitrogen sloshed around Hancock’s bowl like water. It even sounded like water as it splashed onto the ground. But as one girl said, “The carpet! It’s not even wet!”

He even tossed some out into the audience. And after screaming and ducking, the students laughed in amazement that there was nothing on them, except for the feeling of cold.

“That’s awesome,” one boy yelled out after ducking.

Hancock also demonstrated the pressure qualities of nitrogen, by submerging a blown-up balloon into the bowl. The drastic temperature drop made the balloon suck into itself like it was being vacuumed out. Yet as he held it up to show the students, it immediately started expanding again, to full size, all on its own, as the balloon warmed back up.

“This is the relationship between pressure, volume and temperature,” he said.

Of course, the students’ very favorite demonstration was when he turned a regular water bottle into a rocket with just the addition of the nitrogen. The drop in temperature made the water expand, sending the bottle careening off, snaking into the air.

“Can you do that again?” came a shout. And Hancock did, multiple times.

Finally he plugged the water bottle so the water could not escape when the nitrogen was added. Astute budding scientists can guess what happened next. The bottle exploded in a spray of water and plastic, to a similar spray of rousing cheers.

When Hancock finally got to the point of making ice cream right there, the students could not stay seated, they were so fascinated, and probably a bit hungry. But they all got a sample.

“This is fun stuff of science education,” Hancock said after the students filed out with mouthy spoonfuls of fresh ice cream. “I plan to expand our program and go to more schools throughout the state. Our presentation can be targeted to any grade, from first grade on up. That tie we have with education is so unique — otherwise, we’re just another ice cream shop.”

Originally posted at