15 Jul Stem Challenge: Cooking Creations
Next week’s theme is Cooking Creations, so it’s only right that we have a tasty #CMMSStemChallenge! In this activity, you will make your own ice cream in a bag and explore the best way to chill the ingredients in your creamy delicious treat!
Visit our blog every Thursday to see our latest STEM challenge and don’t forget share your creations on social media using #CMMSSTEMChallenge or by emailing firstname.lastname@example.org. Be sure to submit your photos to us by Monday, July 19th!
- Measuring spoons
- Measuring cup
- Half-and-half (Alternatively, milk or heavy whipping cream may be used).
- Vanilla extract
- Salt (Different types of salts will yield different results!).
- Ice cubes (8 cups)
- Small, sealable bags, such as pint-sized or sandwich-sized Ziplocs (2)
- Gallon-size sealable bags (2)
- Oven mitts or a small towel
- Timer or clock
- In each small resealable bag, place one tablespoon of sugar, ½ cup of half-and-half (or milk or heavy whipping cream), and ¼ teaspoon of vanilla extract. Seal both bags well.
- Add four cups of ice cubes to one of the large, gallon-sized bags. Then add ½ cup of salt to the bag.
- Put one of the small bags you prepared into the large bag with the ice cubes. Be sure both bags are sealed shut.
- Put on oven mitts or wrap the bag in a small towel and then shake the bag for five minutes. Feel the smaller bag every couple of minutes while you shake it, and take a peek.
- Add the remaining ice cubes to the other large, gallon-sized bag, but this time do not add salt.
- Put the other small bag you prepared into this large bag. Be sure both bags are sealed.
- Put on oven mitts or wrap the bag in a small towel and then shake the bag for five minutes, as you did before. Again, feel the smaller bag every couple of minutes while you shake it, and take a peek.
- You can also compare how cold the bags feel. Does one feel much colder than the other?
- If you successfully made some ice cream, you can enjoy it now as a tasty reward for your chemistry challenge! If one of your bags did not make ice cream, try putting it back in the large bag that had ice cubes and salt and then shake them for five minutes.
You should have seen that the ice cubes in the large bag with salt melted much more, and felt much colder, than the ice cubes in the large bag without salt. Because it was cold enough (several degrees below freezing), the ice cube bag with salt should have been able to cool the ingredients enough to harden them and turn them into ice cream. In contrast the ice cube bag without salt was not cold enough to do this and the ingredients should have remained fluid. Do not worry, the second bag is not wasted — you can go back and turn the still liquid ingredients into ice cream! Simply put the small bag in the large bag that had ice cubes and salt and shake them for another five minutes.