Kitchen Science Resources

Kitchen Science

Join The Franklin Institute Educators and Executive Chefs from Frog Commissary once a month as we examine topics in Kitchen Science. These fun- and flavor-filled events will engage you in an exploration of food science through hands-on, tastebud-activating activities that help you understand the science behind food and cooking.

View upcoming Kitchen Science events

Kitchen Science is made possible by a grant from the Don Falconio Memorial Fund of the Philadelphia Foundation.

Additional support provided by:

FROG
  • You are what you eat

    Running, singing, thinking, breathing – you need energy to keep your body going! Eating a variety of foods helps you get all the nutrients you need to stay healthy.

    You eat mostly carbohydrates, fats, and proteins that are broken down into energy – measured in calories – to fuel your body. A healthy diet gives you just enough calories to supply the energy your body uses every day.

    But don’t forget the vitamins and minerals in your diet. Although you only need small amounts of these nutrients, they’re essential for the chemical reactions in your body that help you develop and grow throughout your life.

    At Home: A Recipe For Fun

    Ingredients
    • Your dinner
    • MyPlate nutrition guide (available at choosemyplate.gov)

    Directions
    Identify the food groups on your dinner plate.

    Compare the foods on your plate to the MyPlate suggestions.

    Decide how to adjust your food choices for a healthy diet.

    What's Cookin'
    Smell is an important part of sensing flavor. With your nose closed, you don't get the full taste of each food, so it's much more challenging to figure out what it is.

  • Taste with your nose

    As you eat, your senses of taste and smell create the flavor of your food. Then it’s up to your brain to decide whether you like it or not!

    All over your tongue, you have taste buds that recognize five basic tastes: sweet, salty, sour, bitter, and umami (savory). Chemicals in your food stick to these taste buds, which then send the information to your brain.

    But your nose is even better than your tongue at picking up chemicals in your food. It can identify hundreds of different smells. By combining taste, smell, temperature and texture, your brain gets to know an endless number of flavors.

    At Home: A Recipe For Fun

    Ingredients
    • A variety of foods with similar textures (like different flavored jelly beans or ketchup, mustard, and other types of sauces)
    • A friend

    Directions
    Close your eyes.

    Have your friend give you a sample of each food.

    As you eat it, try to identify which food it is.

    Repeat steps 2 and 3, but close your eyes and hold your nose.

    What's Cookin'
    Smell is an important part of sensing flavor. With your nose closed, you don't get the full taste of each food, so it's much more challenging to figure out what it is.

  • Oil and water sometimes mix

    Many recipes call for mixing different ingredients together, but sometimes you need special techniques to combine ingredients that don’t mix easily.

    In certain foods called emulsions, like mayonnaise, you can force oil and water to mix. To make an emulsion, you need to add a third ingredient (such as eggs, in mayonnaise) that sticks to both water and oil, holding the mixture together.

    You can even make mixtures with an invisible ingredient: air. With air whipped into a liquid to make bubbles, foams (like frothy milk on cappuccino) add new flavors and textures to food. But eat quickly – as the bubbles pop, the foam disappears.

    At Home: A Recipe For Fun

    Ingredients
    • Balsamic vinegar
    • Vegetable oil
    • Mustard
    • Two small jars with tight caps

    Directions
    Add 2 tbsp. balsamic vinegar to each jar.

    Add 5 tbsp. vegetable oil to each jar.

    Add 1 tsp. mustard to one jar.

    Cap both jars, shake well, and observe the mixtures.

    What's Cookin'
    When you shake the jars, the vinegar breaks up into small droplets that can mix with the oil. But over time, these droplets combine again, and the vinegar sinks down to the bottom. The mustard makes the emulsion last by keeping the vinegar droplets from coming back together.

  • Tiny microbes in the kitchen

    Not all living things in your food are bad. To make foods like bread, yogurt, and wine, you need live yeast and bacteria to carry out a chemical process called fermentation.

    When yeast eat sugars, they release alcohol and carbon dioxide as by-products that you can use to make different foods. They turn barley or grape juice into beer or wine, and sugar into CO2 that helps your bread dough rise.

    To make yogurt and many cheeses, you use bacteria for fermentation instead. Certain types of bacteria break down milk sugars into lactic acid, which not only creates flavor and texture but also helps prevent spoiling.

    At Home: A Recipe For Fun

    Ingredients
    • A packet of active dry yeast
    • Very warm water (~110˚F)
    • Sugar
    • A large balloon
    • A small empty water bottle

    Directions
    Stretch the balloon by blowing it up and releasing several times.

    Add the yeast and 2 tbsp. sugar to 1 cup water and stir.

    Pour the mixture into the bottle.

    Attach the balloon to the mouth of the bottle.

    Observe for at least several minutes.

    What's Cookin'
    The yeast uses sugar as an energy source to produce carbon dioxide gas through fermentation. With nowhere to escape, the gas rises into the balloon. After several minutes, the balloon will stand up. Wait even longer and the balloon will slowly inflate.

  • A watched pot does boil

    As you heat water to its boiling point, molecules are colliding with each other at high energy. Add your food to the pot, and watch the energy from the water heat up your food.

    When you boil food in a pot of water on the stove, you cook it from the outside in. However, the boiling water is not always at a temperature of 212˚F. Higher air pressure or salt dissolved in the water can result in a higher boiling point.

    You also use water to heat food in your microwave – but unlike the stovetop, it’s the water inside the food. The microwave radiation excites water molecules, causing them to hit other molecules and transfer heat to the food around them.

    At Home: A Recipe For Fun

    Ingredients
    • A pot of water
    • Ice cubes
    • Stove

    Directions
    With help from an adult,put the pot on the stove and heat until the water is boiling steadily.

    While keeping the water boiling, place several ice cubes in the pot.

    Observe what happens to the water.

    What's Cookin'
    When the ice cubes are added, the boiling should stop immediately as the heat flows to the coldest object in the pot. Similarly, when cooking, heat flows to the food in a pot of boiling water until it reaches the same temperature.

  • Fry it up

    When you fry food, you cook it in hot oil or fat. Because oil can get much hotter than water, frying gets your food crispy and browned, with extra flavor added by the oil.

    Depending on how much oil you use, you can deep-, shallow-, or stir-fry your food. The browning of food during frying is one example of the Maillard reaction, where amino acids combine with sugars to create new flavors.

    With frying temperatures around 350˚F, you don’t want your oil to break down from the heat. Vegetable oils withstand higher heat than animal fats. The longer you heat your oil, however, the faster it will break down.

    At Home: A Recipe For Fun

    Ingredients
    • Corn syrup
    • Amino acid caplets (available at health food stores)
    • Nonstick skillet
    • Oven mitt
    • Stove

    Directions
    With help from an adult, put 1 tsp. corn syrup in the skillet on the stove.

    Open one amino acid caplet and pour it into the corn syrup in the skillet.

    Turn the heat to high.

    Move the skillet back and forth to mix the powder, then observe any changes in smell.

    What's Cookin'
    When amino acids and sugars are heated together, they produce a Maillard reaction. If you smell the corn syrup and the amino acid powder before mixing them, you may notice that the chemical reaction creates a new, different smell.

  • Fresh from the oven

    When you bake bread, cakes, cookies, and other tasty treats, you use dry heat to cook food. The heat browns the outside, while also trapping air and changing the form of starch and proteins inside.

    As you mix dough or batter, you add leavening agents like baking soda or baking powder to make it light and soft. These chemicals undergo reactions during mixing and baking that release bubbles of carbon dioxide.

    Inside your dough, the CO2 is trapped in a network of proteins that harden during the baking process. In wheat products, this network is called gluten – the higher the gluten content of your flour, the chewier your food.

    At Home: A Recipe For Fun

    Ingredients
    • Different types of flour, such as all-purpose, bread, pastry, or whole wheat
    • Water
    • Bowls
    • Sink

    Directions
    Measure out 1 cup of each flour into a separate bowl.

    Add ½ cup of water to each bowl and knead until it forms a soft, rubbery ball.

    Let the dough sit for 10 minutes.

    In the sink, rinse each dough under cold water until the water runs clear.

    Repeat for each dough and compare the final texture.

    What's Cookin'
    When you rinse the dough, you wash away all the other components in the flour, leaving only the stretchy gluten. Which type of flour has the most gluten? The gluten content of each flour results in the different textures of various baked goods.

  • An ounce of prevention

    Cooking and eating your food is fun, but don’t forget to keep it safe. While contaminated food can be harmful, simple practices in food preparation and storage can minimize your risk.

    Make sure to wash your produce, utensils, cooking surfaces, and hands to reduce the spread of harmful bacteria. Keep meat, poultry, seafood, and eggs separate – from the grocery store to the refrigerator to the cutting board.

    While you’re cooking, use a thermometer to ensure your food has been safely cooked to at least 140˚F. Once food has been cooked, either keep it hot or put it in the refrigerator to slow bacterial growth.

    At Home: A Recipe For Fun

    Ingredients
    • Vegetable oil
    • Cinnamon
    • Hand soap
    • Sink

    Directions
    Mix some cinnamon and vegetable oil in a small bowl.

    Coat your hands with the mixture.

    Wash your hands in cold water, warm water, or warm water with soap to see which cleans the best.

    What's Cookin'
    Washing your hands right will wash off the cinnamon as well as invisible, harmful bacteria. How long does it take? You should wash for 30 seconds with warm water and soap in order to get your hands clean.