Chemistry classes teach abstract ideas about atoms and molecules. These ideas are often difficult to apply to everyday life. It can be hard to see how what you learn in Chemistry is in any way relevant to your life. The fact is that Chemistry is all around you and understanding it can enrich your daily experience immensely. From food and cooking, to cleaning, to the clothes you wear and the medicines you use to keep you healthy. Chemistry is involved in literally every part of your life.
For this at-home experiment you will make home-made marshmallows. You will learn about how adding sugar makes the boiling point of water rise and how proteins can be shaped into sub-microscopic networks which can trap air bubbles. Do this with some friends and make some hot cocoa on these cold winter days! You will follow a recipe that I have put together based on several recipes I have read. I have made it myself and it is delicious. The recipe is below.
Read the background information available at this link before you begin making the recipe. It will help you to understand the science behind what you are doing. Also, it will be an important resource for answering the questions required for this assignment. Do not do the project described on that page.https://www.sciencebuddies.org/science-fair-projects/project-ideas/FoodSci_p065/cooking-food-science/making-marshmallows#background
Cooking on a hot stove can be a hazard, especially if young children are involved. Sugar solutions become much hotter than boiling water and should be handled with great care.
The stand mixer will be used at high speed. Keeps hands away from moving parts.
You will absolutely need to use a stand mixer, not a hand mixer, for this recipe. If you do not have one I strongly recommend working with a classmate who has access to one. Failing that, a hand mixer may be made to work but only if you take care to use it for a shorter period of time and guard against overheating.
You will need a candy thermometer or an instant-read digital thermometer, as used for cooking meats. It must read to temperatures up to at least 250°F. The thermometer does not have to stay in the pot while you cook. In case you don’t have a candy thermometer, this web page will be useful. From the Exploratorium science museum in San Francisco: The Cold Water Candy Test: https://www.exploratorium.edu/cooking/candy/sugar-stages.html.
For a list of ingredients, see the left-most column of the recipe table below.
|Grease 9x13-in. pan with butter or cooking spray and powder with powdered sugar|
3 envelopes (21 g) unflavored gelatin
a common brand is Knox
|Soak ~10 min. in the mixing bowl of the stand mixer||Once the syrup mixture has reached 250°F, add it slowly to the stand mixer bowl while stirring at low speed with the whisk attachment||
Add the salt, then
mix until it has
about 10 - 12 min.
|Stop the mixer. Add the vanilla extract and mix slowly for about 30 sec.||Use a spatula coated in powdered sugar to put the marshmallow mixture into the pan. Allow to cool in pan for 3 hrs.||Turn marshmallow slab out onto a cutting board sprinkled with powdered sugar. Use a pizza wheel to slice into pieces. Add additional powdered sugar to keep from sticking.|
|½ cup (120 mL) water|
|1½ cups (350 g) sugar||Combine sugar, corn syrup, and water and
boil until the temperature reaches 250°F (121°C); then remove immediately from the heat
|1 cup (240 mL) corn syrup|
|¼ cup (60 mL) water|
|¼ tsp. (1.5 g) salt|
|1 Tbs. (15 mL) vanilla flavoring|
Clean equipment immediately after using because the sugar syrup can harden and become like glass glued to the surface of your pots and bowls. Cleaning up the sugar syrup is easy if you do it right away and use plenty of very warm water. Soaking a pan in hot water for a few minutes before scrubbing it greatly reduces the effort needed to get it clean.
Type a one-page paper which answers the following questions in a numbered-response format. Write no more than one solid paragraph in response to each one. You will be graded based on how clearly you demonstrated significant care in carrying out the experiment and how deeply you have thought about what it means.