I scream, you scream, we all scream for Ice Cream
2006-06-12 04:56:15.000 – Ryan Knapp, Observer
When thinking about summer, one of many images that come to mind is ice cream. It is an indulgent treat that tastes good on a hot, sunny day. Unfortunately, the summit has been in the fog with rain the past several days, so it is neither hot nor sunny. But that has not stopped the summit crew from partaking in this sweet treat. It’s not an easy thing to come by up here though, as ice cream is mostly air, when we bring it up from the valley it will expand, ooze and ruin itself as the air pressure lessens with elevation.
Since state park has gotten a new ice cream machine this spring, we have been accruing our share of ice cream. Yesterday though, we discovered that we had a hand cranked ice cream churner, and it inspired us to create our own sweet concoction. Janet, our volunteer this week, offered to mix us up the ingredients but she stated that we wouldn’t have enough ice. Without hesitation I stated I would FIND her some.
After shift, I grabbed the two summer interns and off we went to the remaining eastern snow field. After battling rain coming at us sideways due to the 45 mph winds and rock hoping slick rocks to avoid stepping on vegetation, we reached the field. After loading a 3000 cubic inch backpack with water logged snow, the journey back up the mountain began. The 45 mph winds and slippery rocks seemed a lot more difficult with more snow on my back then almost my entire weight. After making it back, we started making our ice cream.
After mixing the ingredients, ice and salt were packed around the can and the hand churning began. Science question: Why is salt used with ice? Answer: Ice forms when water reaches 32 degrees Fahrenheit. When you add a catalyst, that temperature drops. (Salt is used because it’s cheap but sugar, alcohol, or other things work as well). For example, when a 10 percent solution is added, the temperature water freezes at is 20 degrees Fahrenheit; 20 percent lowers the freezing temperature to 2 degrees Fahrenheit and so on. This is called a freezing point depression. So the more salt, the lower the freezing temperature is. To make ice cream, you need a temperature below 32 degrees to freezes the mixture. Salt mixed with ice creates brine that lowers freezing from 32 degrees to about 0 degrees.
So things to be learned from this experiment: ice and salt help freeze ice cream, the amount of ice needed only needs to be about a third of the amount we grabbed and I carried, LL Bean rain gear keeps you really dry and warm despite the conditions around you, and ice cream tastes the best when you work for it.
Ryan Knapp, Observer