“Us kids in the Bay Area, we don’t experience snow so a lot of kids don’t know that salt is used to melt icy roads,” said Librarian Angela Ocana, revealing that salt is the secret ingredient in homemade ice cream. Geared toward children in grades two to six, Northside Library’s Sept. 28 DIY Science of Ice Cream event offered 45 kids a hands-on opportunity to make ice cream from a scientific perspective. The Santa Clara City Library Foundation and Friends and the Yahoo Employee Foundation sponsored the event.
“The purpose is to have the kids learn about liquids and solids in a fun and exciting way,” Ocana continued. “Ice has a certain temperature. We take the temperature of ice and add salt. Salt lowers the freezing temperature of the ice.”
First, participants waited in one line to fill a small sandwich size Ziploc bag with half a cup of heavy whipping cream (half and half can also be used), one tablespoon of sugar and half a teaspoon of vanilla. Next, they got into a different line and filled a big gallon size Ziploc bag with ice and salt.
“The ice is now super cold because of its interaction with the salt,” Ocana said. “The kids take their small sealed bag of cream, sugar, and vanilla, and they [put that inside the big bag]. They seal the big bag and shake the bag for about 20 minutes. It’s 20 minutes of pure shaking to get the mixture in the small bag thick. I have some sprinkles and chocolate chips for the kids to add in.”
Some children came prepared with mittens to keep their hands warm from the ice as they vigorously shook their bags. By the end of the hour, a number of children had a dessert spoon in one hand and their opened sandwich bag filled with freshly made ice cream in the other.