Cooking is a combination of art, math and science. The art part is making the food items look presentable, attractive and mouthwatering. There are elements of math involved–measuring, doubling a recipe, halving a recipe and calculating the correct amount of time and temperature to produce results. The science part is knowing how to heat, cool and combine different ingredients to produce edible and tasty products. All of these skills are addressed in a home economics class. If you need to add more science and math to your home economics class, involve dry ice in the following candy making method.
Start with a purchase of dry ice in the form of blocks. Plan on teaching a hard candy class the day your dry ice arrives. With some dry ice providers, you can schedule the exact day and time to deliver the ice. You may want to take advantage of this scheduling service as dry ice will begin to evaporate the minute it is exposed to the air in your classroom.
Next, decide if your students will practice making brickle, toffee or hard candies. You may even offer them the choice. Show them how to handle the dry ice so they don’t “freezer burn” their flesh off. It should only be handled with special gloves and the blocks need to remain covered in cloth to prevent accidental contact until it is time to use their freezing properties.
Have them boil the water needed or create and boil their candy base. Non-stick aluminum foil should replace the cloth over the top of the dry ice and lay nice and flat. The candy bases for brickle and toffee are then spooned over the aluminum foil, which should be sufficiently chilled by the dry ice underneath to cause the candy to freeze, crackle and crack almost instantly.
Instruct your students to carefully remove the aluminum foil, with gloved hands/properly protected skin. Set the dry ice out of the way where no one can accidentally touch it. Then sample your students’ cracked candies for taste and effective execution.
Wrap up the Class By Explaining How Dry Ice Works
By teaching your home economics class how dry ice works, what it is (a frozen gas), and how they can use it to speed up the freezing and hardening steps of many desserts and dishes, they can try using it at home for special occasions. You may even provide them with a handout on the properties of dry ice, how it is used by famous chefs and where they can purchase small amounts of dry ice on their own. Chef specialty and restaurant supply stores ship dry ice on demand, but it should be used within forty-eight hours of arrival or it will dissipate into thin air (literally!) and then your students would have to reorder it or use “Plan B” to rapidly freeze or cool their creations.