2010-05-01 11:44:24

Chemistry department hosts ice cream themed Explorer Cafe

1. Chemistry department hosts ice cream themed Explorer Cafe

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Written by Luke Harold Collegian Editor

La Salle’s Chemistry Department led a presentation on the history of ice cream and how to make ice cream with liquid nitrogen in the final Explorer Café event of the year.

Dr. Michael J. Prushan, an assistant professor of inorganic chemistry, along with Dr. William A. Price, a professor of organic chemistry, led the discussion.

Prushan began the presentation by giving an overview of the history of ice cream:
-400 B.C.:  Alexander the Great occasionally sent his servants to mountainous regions to collect snow and ice, which was brought back and mixed with fruit nectar.
-618 A.D.:  Some people used milk from animals such as cows, goats and buffalo to create a substance that roughly resembled ice cream.
-1664:  In Naples, Italy, people combined ice with sweetened milk. Also at this time, Charles I paid his head cook extra to keep his ice cream recipe secret.
-1774:  The first ice cream parlor opened in New York City.
-1812:  Aunt Sallie Shadd, a former slave, began making ice cream as we continue to make it today.

Prushan then demonstrated the effects that liquid nitrogen had on various objects. 

For example, he placed a racquetball inside a container of liquid nitrogen.  He then bounced a different racquetball to demonstrate that a normal one bounces when thrown toward the ground.  When he took the first racquetball out of the liquid nitrogen container, it hit the ground and collapsed into itself, making a shattering sound.

In another example, Price put a small balloon filled with air into the liquid nitrogen container.  Upon taking it out, the balloon was shriveled up before it gradually began to expand into its original shape.
Prushan then called four student volunteers to attend to two metal bowls.  With two students on each bowl, ingredients such as cream, sugar, chocolate syrup and vanilla extract were poured into the bowls and the students stirred the contents as Price poured liquid nitrogen into each bowl.

After several minutes of stirring, the liquid nitrogen ice cream was complete and attendants were free to sample the result.