Save your eggshells, and use them to make a batch of eggshell sidewalk chalk with your kids. This is a quick and easy project that’s sure to blow their minds. Even my teenagers were impressed.
Since eggshells contain calcium carbonate, the main ingredient in store-bought sidewalk chalk, they’re the ideal material for a batch of homemade sidewalk chalk, and a fun way to reuse something that most people throw away.
Want to try this project with your kiddos? Here’s a step-by-step tutorial to take you through the process.
Eggshell Chalk Recipe
9 large eggshells will make roughly one stick of sidewalk chalk, so you may want to save up your eggshells, until you have a bunch.
What You’ll Need:
- Eggshells (any color is fine)
- All-purpose flour
- Measuring spoons
- A bowl
- A spice/coffee grinder, blender, food processor or mortar and pestle
- Food coloring
What You Do:
Wash and dry your egg shells. Then, place them in a spice/coffee grinder, blender, food processor or mortar and pestle, and grind them into a fine powder.
A blender or food processor will give you a coarser grind. A spice/coffee grinder will give you a finer grind. Either consistency will work in this recipe, so use whatever you’ve got.
If you decide to use a food processor or blender, just know that the eggshells are likely to etch the pitcher. I keep a cheap yard sale blender on hand for craft projects like this.
Grinding eggshells can get kind of dusty, so you may want to take this project outdoors.
Be sure to let the dust to settle, before you open the lid, or you’ll get a face full of eggshell powder.
To make your first stick of eggshell sidewalk chalk, combine 3 Tablespoons of eggshell powder, 1 Tablespoon of all-purpose flour and 1 Tablespoon of water in a small bowl. Knead until the ingredients come together and form a dry dough.
Then, knead in several drops of food coloring. 7 drops produced the vibrant colors you see here.
Tip: Wear gloves, if you don’t want your hands to get stained by the food coloring.
When you’re happy with the color, shape the dough into a chunky stick of sidewalk chalk …
and place it on a baking sheet. Then, repeat the process, until you’ve made as many sticks as you’d like.
You can also press your chalk dough into silicone molds, if you want to make shaped chalks.
To dry your chalk, simply leave it out to air-dry for four or five days, flipping it occasionally, so it dries on both sides. or pop it in the oven at the lowest temperature setting for 90 minutes. Flip it halfway thorough; then, allow it to air-dry for another 24 to 48 hours, or until it feels dry to the touch.
I’m a fan of the air-dry approach because it’s basically hands-off, but if you have young kids, who are eager to try their chalk, you might want to go the oven route.
Eggshell sidewalk chalk produces vibrant pictures, just like the store-bought kind. But just like the store-bought stuff, it should only be used on sidewalks. It’ll scratch chalkboards and other smooth surfaces.