Purpose:
The purpose of this experiment is to find out how the recipe of making ice cream in a baggie can be altered to make the ice cream smoother.
Hypothesis:
Let n=the right amount of salt for the perfect ice cream. If the amount of salt used is greater than n, then the ice cream will be too thin. If the amount of salt used is less than n, then the ice cream will be too thick.
Materials:
1. ½ cup milk 2. ½ cup whipped cream 3. ¼ cup sugar 4. ¼ teaspoon vanilla 5. ½ to ¾ cup sodium chloride (NaCl) as table salt or rock salt 6. 2 cups crushed ice 7. 1 quart size Zip-loc bags 8. 1 gallon size Zip-loc freezer bag
Method: Note: The purpose of this experiment is to alter the recipe. This method is the standard. Feel free to alter anything. …show more content…
1.
Add 1/4 cup sugar, 1/2 cup milk, 1/2 cup whipping cream, and 1/4 teaspoon vanilla to the quart ziplocTM bag. Seal the bag securely. 2. Put 2 cups of ice into the gallon ziplocTM bag. 3. Use a thermometer to measure and record the temperature of the ice in the gallon bag. 4. Add 1/2 to 3/4 cup salt (sodium chloride) to the bag of ice. 5. Place the sealed quart bag inside the gallon bag of ice and salt. Seal the gallon bag securely. 6. Gently rock the gallon bag from side to side. It's best to hold it by the top seal or to have gloves or a cloth between the bag and your hands because the bag will be cold enough to damage your skin. 7. Continue to rock the bag for 10-15 minutes or until the contents of the quart bag have solidified into ice cream. 8. Open the gallon bag and use the thermometer to measure and record the temperature of the ice/salt mixture. 9. Remove the quart bag, open it, serve the contents into cups with spoons and enjoy!
Observations: Note: Observations may vary depending on alterations in the
method.
Temperature of ice before step 7: -3°C
Temperature of ice/salt mixture: -5°C
Conclusion: Ice has to absorb energy in order to melt, changing the phase of water from a solid to a liquid. When you use ice to cool the ingredients for ice cream, the energy is absorbed from the ingredients and from the outside environment (like your hands, if you are holding the baggie of ice!). When you add salt to the ice, it lowers the freezing point of the ice, so even more energy has to be absorbed from the environment in order for the ice to melt. This makes the ice colder than it was before, which is how your ice cream freezes.