Dry Flowers Using Silica Gel Beads – Fun Desiccant Science Project

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It's easy to dry flowers using silica gel as a desiccant. (Jason Wong)
It’s easy to dry flowers using silica gel as a desiccant. (Jason Wong)

Do you admire the simple elegance of dry flowers? Here’s a science experiment that makes use of those little packets that say “Do No Eat” you find with shoes, electronics, and other products. The packets contain silica gel beads, which are silicon dioxide (sand) with a porous surface. The pores adsorb and trap water, so the beads are used as a desiccant (to keep things dry). You can study the desiccating property of the beads while making a dried flower, to keep or give as evidence that you learned something about science.

Flower Drying Project Materials

You only need a few basic ingredients for this project:

  • Fresh flowers
  • Small container with a lid (like a baby food far)
  • Packets of silica gel beads

How To Dry Flowers Using Silica Gel Beads

All you need to do to dry a flower using silica is to seal the flower with the gel beads overnight. The trick is to make certain the gel beads don’t already contain water, which they might, if they have been sitting around your house for a few months. You can use your uncertainty about the beads to perform scientific measurements.

  1. Make sure your flower will fit inside the container and that the lid of the container forms a tight seal. You don’t need humid air getting into your jar.
  2. Use a balance or scale to measure the mass of the silica gel. Record the value.
  3. Measure the mass of your fresh flower, which contains water. Record the value.
  4. Silica gel beads are reusable. Once they have adsorbed water, you can recharge the beads by gently heating them. Heat the gel beads a pan over a burner for 10-15 minutes or place them in a warm over for 30 minutes.
  5. Let the beads cool and them weigh them on the scale. Record the value. How much water was removed from the beads by heating them?
  6. Pour some of the dry beads into the jar. Add the flower. Pour the rest of the beads into the jar. It’s fine if you don’t fill the whole space of the jar with the silica and flower. You only need enough gel to capture the water from the flower.
  7. Seal the far and allow time (overnight) for the gel to adsorb water.
  8. Remove the flower from the gel. Weigh it and determine how much water was removed.
  9. Remove the gel from the jar. Weigh it and determine how much water it gained.

If the flower is not completely dry, you can recharge the gel beads, cool them, and repeat the process. Don’t throw out your gel beads at the end of the project. They don’t ‘wear out’, so you can use them again and again.