Read the entire introduction, the linked pages from the intro., and the recipe before you begin to work on making marshmallows.
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 on the next page.
Marshmallows are the perfect combination of science and the art of candy-making. 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 also need a candy thermometer or an instant-read digital thermometer. 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.
Read the background information available at these links 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 the Science Buddies page.
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.
For those who must avoid animal products, gelatin can be a concern. It is made from connective tissue from pigs or cows, or both. A beef-only gelatin is available for those who must avoid pork. For those who must avoid both, it may be possible to use agar or carrageenan as a substitute for the gelatin. Reportedly, 1 teaspoon of agar replaces one envelope of powdered gelatin. I have not tried it and if you do, make a point of saying how the recipe worked for you in your report. The vanilla extract will be a problem for those who may need to avoid alcohol ingredients. Alternatives exist (like vanilla sugar or alternative flavors) and if you can’t find a suitable one then consult with your teacher.
An alternative recipe that gives your marshmallows a maple flavor uses 1 cup corn syrup, 1 cup maple syrup, and 1/2 cup sugar with no water added to the sugar mixture before boiling. Add only about 1 tsp. vanilla to allow the maple flavor to shine through. When cooking be very careful about boiling over as the maple syrup tends to foam. Remove from the heat if it starts to boil over. Use a taller pot to help avoid this catastrophe.
Grease a 9 x 13-in. pan with butter or cooking spray and powder with powdered sugar. Set up the stand mixer near the stovetop and attach the whisk attachment.
Empty three packets of unflavored gelatin into the mixing bowl of the stand mixer. Add ½ cup water. Soak the gelatin for at least 10 min while you prepare the rest of the recipe. Set aside.
Combine sugar, corn syrup, and ¼ cup water and boil in a small pot (2 qt or so) so that the thermometer will have enough liquid to be able to measure the temperature. Cook just until the temperature reaches 250°F (121°C); then remove immediately from the heat. This will take only about 5 minutes or so. Use the temperature or the cold water candy test to be sure. Turn the stand mixer on to stir at low speed while you pour the syrup mixture into the bowl. Stop the mixer and use a spatula to make sure everything is mixed together before turning it to high speed.
Add the salt, then mix on the mixer’s highest speed until it has fluffed up, about 6 - 10 min.
Stop the mixer.
Add vanilla extract and mix slowly for about 30 sec or until fully incorporated. Turn off the mixer and then use a spatula or large metal spoon coated in powdered sugar to put the marshmallow mixture into the pan. Allow to cool in the pan for 3 hrs.
Turn marshmallow slab out onto a cutting board sprinkled with powdered sugar. Use a pizza wheel to slice into pieces. Dust with powdered sugar to keep from sticking. You may also use cookie cutters to make custom-shaped marshmallows. Store for up to three weeks in an airtight container.
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.