Science in the Kitchen

You don’t need to build a lab to teach your children about science in your home; you already have one! It is your very own kitchen. Kids love learning how to prepare food and doing so together in your kitchen will give them first-hand experiences that will show how many basic scientific processes work. Plus, they will be learning about important math concepts like working with fractions. Food preparation also gives you a chance to teach children about kitchen safety. You will want to carefully supervise your children as they work in the kitchen and be sure to help them when using the oven, stovetop, and any sharp tools needed in a recipe.

Observe How Plants Get Water

In this kitchen activity, children will learn how a plant’s roots, stem, and xylem work together to carry water into the leaves of a plant. Xylem are a series of tubes throughout the leaves of a plant. They are easy to see in leafy greens such as iceberg lettuce. Have children imagine how the plant had worked out in the field before being harvested. Examine where the stem had been and explain that this originally was connected to a root system. Discuss how water from rain or an irrigation system fell onto the soil and then traveled through the roots, stem, and eventually the xylem.

Fill a bowl with water and add to it several drops of food coloring. Next, arrange a few leaves of the plant in the bowl so that the bottom is submersed but the tops of the leaves are sticking out. Allow the lettuce leaves to sit in the water for 4 or more hours. After the time has passed, you will notice the color of food coloring is now evident in the leaves. The deeply concentrated colored areas display where water traveled through xylem before moving throughout the rest of the plant. This scientific lesson can also be demonstrated using celery or carnations.

Apply Pressure to Gas

Gas molecules move faster when their temperature begins to rise. As their speed increases, their direction of movement changes once they begin bouncing off each other. These collisions cause the molecules to move even farther apart. Heat, therefore, causes gas to expand. Baking popovers allows kids to see the result of this.

In a large bowl, have your child combine a half cup of flour and a teaspoon of salt. Add a generous amount of fresh pepper. Next, combine two eggs and ¾ cup milk to the mixture in the bowl. Whisk this batter until it is smooth. Prepare a 6-cup muffin pan by adding to each cup a teaspoon of vegetable oil. Place it in the middle of an oven preheated to 450°. You’ll know it’s ready when you detect smoke coming from the hot oil; this should take about 10 minutes. The outsides of the popovers will begin to cook immediately when the pan has been preheated.

Carefully remove the pan and cautiously add batter to the muffin pan. Fill each muffin cup about 2/3 of the way full. Replace the pan into the oven and bake for 15 to 20 minutes. Resist peeking at your popovers by opening the oven door. Your oven will lose too much heat if you do. Once the time is up, remove any steam in your oven by slowly opening the oven door. After it has escaped, close the oven door and bake for an additional 8 to 10 minutes at a reduced temperature of 375°. The popovers should be golden and crisp.

While the popovers had been cooking, a tight seal formed from the proteins and starches in the flour and eggs. As both ingredients were being heated, evaporation of the liquids occurred. The gas tried escaping, but it was trapped by the already-cooked outer layer of batter. This layer, however, will have been stretched by the gas as it expanded, making the cooked batter pop over the top of each muffin cup. While your popovers will have a fluffy inside, their outsides will be crisp.

Acid and Base Reactions

Baking banana bread is a great way to see the results of a chemical reaction. This recipe requires two ingredients that are highly reactive. The molecules in buttermilk, an acid, and baking soda, a base, are highly reactive. When mixed in this recipe, the molecules in each of these key ingredients rearrange to make something new and delicious. The atoms in baking soda react with buttermilk so that carbon dioxide is released. These gas bubbles puff up the batter so that after baking you have soft, fluffy bread.

The oven will need to be preheated to 325°. Grease and flour a large loaf pan or two small ones. Whisk together 2 eggs, 1/3 cup buttermilk, ½ cup vegetable oil, and three mashed bananas. In a separate bowl, sift 1 ½ cups sugar, 1 ¾ cups flour, a teaspoon of baking soda, and ½ teaspoon of salt together. Add these ingredients to the banana mixture. Mix all ingredients together well. Slowly pour the batter into the loaf pan. Bake this in the center of the oven for about 80 minutes. Before removing the pan to cool, check to see that it is thoroughly cooked by inserting a toothpick into its center. Notice how much taller the top of the loaf has become. If the toothpick does not come out clean and instead has raw batter clinging to it, bake for an additional 10 minutes; repeat if necessary. Place on a cooling rack when baking is complete.