Sweet Potato Fries


3 large sweet potatoes

Time: 30 minutes

Sweet potatoes are a great vegetable to teach out physical and chemical changes produced by cooking.


  1. Cut the sweet potatoes into big slices so that it is easier for students to handle. You can peel them or leave them unpeeled.
  2. Cut the chunks into small, bite-sized cubes. For this one, make sure that the cubes are pretty small: sweet potatoes take a while to cook, so the smaller pieces will cook faster.
  3. Heat some oil in the pan over medium-high heat.
  4. Cook the sweet potatoes until they are golden-brown. This will take about 10-15 minutes, depending on how small the pieces are.
  5. Add salt and pepper to taste.


This is an excellent lesson to explore chemical and physical changes. Have students try a piece of raw sweet potato and note its flavor and any other characteristics. After cooking, taste the fries. Did they get sweeter even though we didnÍt add any sugar? Did the smell change? Is it still crunchy or did it get softer? What physical changes did we cause to the sweet potatoes?