Recreating the past – Coffee grounds fossils (4th Grade)

Without fossils, we would know nothing about prehistoric life. Fossils are the remains of animals and plants that died a very long time ago and became preserved in rocks. These remains are our window on the past. They show us the amazing variety of life that thrived and then disappeared over millions of years of Earth’s history.

Fossils are preserved remains of once-living things, such as bones, teeth and claws. Usually the remains were buried in sediments – layers of tiny particles such as sand, silt or mud. Very slowly, the layers and the remains inside them turned into solid rock.





We need:

  • 1 cup of used coffee grounds.
  • 1/2 cup of cold coffee.
  • 1 cup of flour.
  • 1/2 cup of salt.
  • Wax paper.
  • Mixing bowl.
  • Starfish, seashells, small dinosaurs, or other objects for the impressions.
  • Empty can or a butter knife.



  1. Stir together the coffee grounds, coffee, flour, and salt, until well mixed.


  1. Press the small objects firmly into the dough, to leave an imprint. Remove the object, and there’s your fossil! You can use a toothpick to poke a small hole near the edge of the coffee ground fossils, if you want to hang it later.


  1. Let the coffee ground fossils dry and harden overnight.


One of our fossils: