Every so often I gather our science books, a packet of sticky notes, and ask my children to mark which projects and topics they'd like to explore. Projects, where sweet things are used or created, get marked often. So I was not surprised when flipping through one of our favorite books, Usborne's 50 Science Things to Make and Do, I found a flag on "Meringue Science."
My mother made meringue "forgotten cookies" for Christmas every year. Dyed pink for the almond flavored ones and green for mint, packed full of chocolate chips, I remember coming downstairs to our kitchen countertops covered with trays of puffy meringue clouds.
A little nostalgic, and having never made meringue cookies with my kids, I put the book in our "to do" bin.
We'd only need egg whites for the cookies, so what could we do with the yolks? I kept flipping. I moved on to the next book, Totally Gross Chemistry. Halfway through, the title "Yucky Yolk" caught my eye. Mayo! Our son's new favorite condiment. Although the book suggested not eating the mixture (maybe because of the raw eggs) a quick Google search confirmed I'd found a basic recipe for mayonnaise.
While I love and use activity books geared for children, I often find when we follow them we need extra resources or tweaking. Or maybe I'm just not great at following directions. Either way, for the cookies we followed my mother's recipe and used the Usborne book to explain why meringue does what it does, and for the mayo, we watched this video, and I combined a couple of recipes. We used the activity book to explain the chemistry we were witnessing.
Below are the recipes we used, links, and questions to help you explore.
Cooking is my go to activity when we are seeking a project or way to spend time together. It offers countless opportunities for children to engage in learning. Like practicing collaboration, which among siblings I am often trying to encourage. One child reads while one gather's ingredients; one stirs, and the other pours. Reverse, so everyone gets a turn. As long as there is something great to eat at the end, my kids are usually pretty excited and willing to cook AND work together.
Meringue cookies and mayo might be the perfect foods to make at the same time. Their simple ingredients and easy to follow recipes allow for children and adults of any age to participate in the magic of edible chemistry, create good food, and hopefully find some joy while doing so.
TIP- Licking the beaters adds extra joy!
Kitchen Chemistry- Meringue Cookies & Mayo (probably best eaten separately)
For Meringue: 2 egg whites, 3/4 c sugar, 1 tsp cream of tartar. Optional ingredients- a handful of chocolate chips, food coloring (we use India Tree), flavoring (mint, almond). Tools- 1 bowl, beaters, parchment lined cookie sheet, spatula, two spoons.
For Mayo: 2 egg yolks, two tsp of lemon juice, 1/2 TB of vinegar, 1 c oil (I used olive oil. Safflower or corn work too), 1/2 tsp salt, 1 tsp dijon mustard. Tools- immersion blender (you could do this with another type of beaters/blender, but you won't see emulsion as well), 2 bowls or 1 bowl and a large measuring cup, whisk. If you use an immersion blender, a large measuring cup is nice because it keeps the splatter down and your child can see the egg emulsify the oil/acid.
**Teach your child/children how to separate an egg if they don't already know how. Have extra eggs on hand. Put yolks in one bowl and whites in another.
All the rest of the steps assume a child is following them with adult assistance if needed.
1. Preheat the oven to 375°F
2. Pour 1 cup of oil into either a large measuring cup or an empty bowl.
3. Add 2tsp of lemon juice and 1 TB of vinegar to the oil.
What is happening? What is the vinegar doing? Why do you think they look the way they do?
4. Whisk up oil and acids (vinegar and lemon juice).
Now, what has happened? How come? Let the liquid rest, but keep your eye on them. See if they change?
5. Use an electric mixer to mix your egg whites.
Watch what happens? Why are they foaming? Answer- You're adding air into their structure (water protein solution). See the air pockets. Learn more about eggs and their science.
6. Add the tsp of cream of tartar and slowly continue to beat while slowly adding the sugar. You want to stop when the meringue forms mountain peaks that don't fall.
7. Using your spatula, fold (lightly stir) in your optional ingredients. Just a drop or two of flavoring is needed. Add food coloring until you get your desired result. You could also divide the mixture if you wanted two colors. Don't forget chocolate chips- a handful or two and a couple to try.
8. Using two spoons, plop a large spoonful of meringue onto a parchment lined cookie sheet. Try to keep them in blobs and try not to let them touch.
9. TURN OFF THE OVEN. These are cookies that can be forgotten, hence their name.
10. Put cookies in the oven and allow them to "cook" for at least four hours. Overnight works too.
11. Go back to your oil and acids.
What has happened? How come?
12. Add your egg yolks to the oil/acid mixture. If you're using an immersion blender, add yolks to the measuring cup so you can see clearly how the ingredients begin to mix. If you're using another type of blender, mix ingredients how it makes sense to do so.
13. Turn on mixer and watch what happens.
What about the egg yolk lets oil/acid mix? Head back to here to read about why egg yolks create this emulsion.
14. Stir in 1 tsp of dijon and 1/2 tsp of salt.