A slice of pizza is a fun food science experiment. Why does the dough rise? Why does cheese melt? And why is pizza everyone’s favourite food?
A homemade pizza party is a great way to engage kids in the science of cooking. Kids can help dice up ingredients, grate cheese and create their own masterpieces. Turning pizzas into artwork can encourage children to try new vegetables. Create a garden with broccoli for trees, or a face with olives for eyes and a red pepper mouth. Make a pizza rainbow with all sorts of different coloured vegetables.
Why does pizza taste so good?
What is there not to like about pizza? It’s a combination of bread, cheese and your favourite toppings. However, there is a scientific reason why pizza tastes so good … and it all comes down to a secret ingredient, MSG.
MSG isn’t just a flavour additive; it also occurs naturally in all sorts of foods. A few foods that contain MSG are wheat, tomatoes, cheese, mushrooms, pepperoni and pizza!
Here’s the science behind why MSG makes food taste good. MSG stands for monosodium glutamate. Glutamate is an excitatory neurotransmitter, which means that it causes neurons to be excited. Our body makes glutamate and uses glutamate all the time. When we eat foods that have MSG, it makes our taste buds excited. This means all flavours become more flavourful and delicious when there is MSG in the food.
Why does dough rise?
Pizza dough, like most other types of bread, uses yeast to help it rise.
• Yeasts are tiny single-cell organisms. A single yeast is very tiny and each grain in a package of instant yeast is actually a bunch of yeast.
• Yeast eats sugar and turns it into carbon dioxide (bubbles) and alcohol. This is called anaerobic respiration, which means it’s done without oxygen.
• When we make bread, the yeast eats the sugars in the flour and leaves the gluten protein behind. This gluten forms a sticky bubble that fills with carbon dioxide like a balloon.
• To see the yeast in action, pour about 4 cm of water into the bottom of a clear plastic water bottle. Add in 1 Tbsp of sugar and 1 Tbsp of dried instant yeast. Cover the top of the bottle with a balloon and shake to dissolve the sugar and yeast. After about 15 minutes, the balloon will start to inflate. This is the yeast eating the sugar, multiplying and releasing carbon dioxide.
Traditional Pizza Dough
Making dough is fun! It’s neat to watch the yeast bloom and see how the dough rises. Kids love to knead dough and form pizza crusts.
If it’s a hot day, bake the pizza on the barbecue. The trick is to make small pizzas, which are easier to manoeuvre. After rolling out your pizza dough, brush it with olive oil and grill for 2 minutes. Flip the crust, quickly add the toppings and grill for another 3 to 5 minutes, until the cheese has melted.
11⁄2 cups water
1 envelope instant dry yeast (21⁄4 tsp)
1 teaspoon sugar
2 tablespoons olive oil (plus more for coating the dough)
31⁄2 to 4 cups of all-purpose flour
2 teaspoons salt
More flour, as required for rolling out the dough
1. Mix the water, yeast and sugar in a large bowl. Leave the yeast to bloom for 5 minutes. Then mix in the oil, followed by the flour and salt. The dough will be very sticky. I recommend coating your hands with a little bit of oil and then kneading the dough until it’s smooth and elastic. Children can help with this step if they want.
2. When you have a nice smooth ball, coat it with a drizzle of oil. Cover the dough with a tea towel and let it rise for 1 hour.
3. After 1 hour, punch down the dough and divide it into 2 to 4 balls, depending on how large you want the crusts to be. This recipe will make two 12-inch crusts or four 9-inch crusts. Cover the dough with a tea towel, and let it rest.
4. Preheat the oven to 475°F. Prepare all the toppings. Once the oven has preheated, form the pizza crusts.
5. Roll out the pizza dough on a lightly floured surface. Sprinkle two baking sheets with cornmeal and place the pizza crusts on the baking sheets. Decorate the crusts with your favourite toppings. Bake for 15 to 20 minutes, until the cheese is melted and the crust is golden brown.
