Book Review
Science Experiments You Can Eat

Illustration by Elizabeth Carney Sowards

RED CABBAGE INDICATOR (adapted) MATERIALS: 1 whole red cabbage, water, knife, grater, two large bowls, measuring cups and spoons, slotted spoon, strainer, clean glass jar and cover, small white dish. Cut cabbage into quarters and grate each section into a large bowl. Add enough water to cover the cabbage and let stand, stirring occasionally. When the water is a strong purple, remove as much of the grated cabbage as you can with slotted spoon and save it in second bowl. Pour the purple solution through the strainer into the glass jar. Put about a tablespoon of your cabbage-juice indicator into a small white dish. Test for an acid by adding a substance you know to be an acid (such as lemon juice) to the cabbage juice. Notice the color it becomes in acid. Now use a fresh sample of cabbage juice and add a substance you know to be a base (baking soda). Now add acid to the base-and-indicator mixture to reverse the color change. What happens when you add base to the indicator showing the acid color? Sample foods to test: Cooking water from boiled vegetables; liquids from canned vegetables and fruits; cream of tartar; soda; egg whites; fruit juices; tomatoes; cottage cheese. TO EAT THE CABBAGE: You can use the grated red cabbage raw in a salad or cole slaw, or saute with olive oil, garlic, and salt. The book also offers another experiment to do with the raw cabbage.

SPINACH (COLOR CHANGES IN CHLOROPHYLL) (adapted) MATERIALS: milk; water; several fresh, washed spinach leaves; measuring cup; 2 saucepans; slotted spoon; white plate. EXPLANATION: When fresh spinach is first put in boiling water, its green color brightens as gases in the cells are forced out by heating. After this, the spinach becomes grayer and grayer. Cooking releases certain acids in spinach that change the color of chlorophyll. When chemists want to prevent a solution from becoming too acid or basic, they use a kind of solution called a buffer, which can absorb any acid or basic molecules and take them out of a solution. One substance we can eat that can act as a buffer is milk. Is it possible to preserve the color of spinach by cooking it in milk? Do this experiment to find out. 1. Put 1 cup of milk in one saucepan and 1 cup of water in the other. Warm the liquids over low heat. When they begin to simmer, drop a few leaves of spinach into each pan. Keep the temperature low so that the milk simmers but doesn’t boil. Cook the spinach for 4 or 5 minutes. Turn off the heat and let the spinach stay in the hot liquids for another few minutes. Remove the spinach with a slotted spoon to a white plate and compare the colors of the cooked spinach leaves to each other and to a raw spinach leaf. Observations: Have the colors changed after cooking? Which seems grayer, the spinach cooked in water or the spinach cooked in milk? Which tastes best to you: the spinach cooked in milk or water or raw spinach? Choose either milk or water to cook the rest of the spinach. Season with salt, pepper, and butter to serve.

By Vicki “Science Power” Cobb
Reviewed by Judy Sobeloff
from the June 2007 Newsletter

Since my Meals Kids Might Eat (Meals Parents Might Cook) debut last month, I’ve been amazed by the number of times newsletter readers have engaged me in the following conversation:

Other person: So what do kids eat besides macaroni and cheese?

Me (stumped): I don’t know. That’s what I’m hoping to find out.

Other person: Oh yeah. They also eat grilled cheese.

This month in our search for Food Beyond Cheese, we turn to science. Or, more specifically, to Science Experiments You Can Eat by Vicki “Science Power” Cobb.

I admit I stacked the deck, inviting over one scientist friend and marrying another. But don’t worry, as this book could be used successfully by anyone who enjoys doing projects with kids. While it seems geared toward elementary school students, I think it would work well with kids of any age. With my deadline fast approaching, rather than wait a few years, I chose to work with the four preschool-aged kids we had on hand.

Initially some of the junior scientists were not eager to participate (“There’s no toys in the kitchen!”) but all of them quickly came around, especially after I dropped a bowl, with everyone noting in the most scientific way how cleanly it split apart.

The book contains a variety of recipes, including those that can be done quickly and those that take weeks (rock candy). The foods involved range from Kool Aid and hard candy to spinach and squash. While not a cookbook per se, most of the experiments can be converted into dishes designed to be eaten. Given my nutritious intentions, I steered clear of the sugar bombs and headed for the vegetables. My experimental question: Will investigating food in this way make it more palatable for kids?

First, we made Red Cabbage Indicator, which immediately got the kids interested in “tasting purple” (“It’s sweet.” “It’s zingy.” “No!”) Fred got into the spirit, too, as the kids poured water over the cabbage they had grated: “Come play with it! Come feel it!”

We tested several items on hand, including lemon juice, baking soda, and vinegar to see whether they turned the indicator red (as do acids) or blue (as do bases). Then we mixed acids and bases together and watched the carbon dioxide created fizz.

Following a suggestion from the book, Fred mixed the kids’ grated cabbage with olive oil, garlic, and salt, which all the adults and most of the kids found delicious. A bonus, since they likely would not have tried it otherwise.

Our second experiment, “Striped Celery Snack,” in which a piece of celery is supposed to drink water dyed red, we deemed a failure. Perhaps we needed stronger dye. The only kid willing to taste the dyed celery rated it “not good.”

Next up was nut butter. Step one: light a nut on fire. As the initial flame was not quite huge enough for Fred’s taste, he improvised a pedestal by impaling a pecan on a nail, quick to explain that nuts burn better when vertical. I’m sure every family has their idiosyncrasies. Step two, which the kids loved: grind nuts in nut chopper. Though the resulting nut butter was dry, the kids ate it up.

At this point, they got into the dress-ups, and we discovered that wearing a pink wig helps with whatever you’re cooking.

For the grand finale, we experimented with spinach (“Color Changes in Chlorophyll”). I predicted the kids would be enticed to eat the results, but Lisa, ever the skeptic, predicted “no way.”

I don’t want to ruin the surprise of which version we universally liked better, but suffice it to say, as Lisa did, “It got my kids to eat three good bites of spinach (comparing the three varieties) and they ate it thinking about which tasted best rather than thinking ‘eww, spinach.’”

Our conclusion: Getting to play with the food in an experimenting way helps kids become more familiar and comfortable with different foods, and ergo, more willing to try them. They definitely learned about various properties of foods and enjoyed doing it, and they sampled various vegetables and mostly liked them, which for me makes this book worth our while.

Vicki Cobb, Science Experiments You Can Eat (New York: HarperTrophy, 1994). 214 pp. $5.99.

Judy Sobeloff thanks Betsy at BookPeople for recommending this book (and for much more.)

© Copyright on articles, recipes and images are jointly held by the Moscow Food Co-op and the respective contributors, except were otherwise noted.

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