You can build a relatively inefficient but fun-to-watch distiller at home. Avoid the steam produced in this activity—steam burns can be particularly harmful.
Step 1: Fill a cooking pot to a depth of about 1 cm. Add food coloring or some salt or both.
Step 2: Place a heavy ceramic coffee mug in the center of the pot. The height of the mug should be at least 1 inch below the height of the pot.
Step 3: Lay plastic wrap loosely across the top of the pot and secure it with a rubber band. The seal should not be airtight—leave two of the edges open to prevent a buildup of pressure. Trim away excess plastic wrap. Place an ice cube at the center.
Step 4: Put on safety glasses and turn the burner on low to bring the water to a low boil. Look for signs of cloud formation below the ice cube. Once the water is boiling, the mug may jostle.
Step 5: Turn off the heat. Remove the melted ice with a sponge. Why isn’t the solute carried over into the mug? How much distilled water are you able to collect per ice cube? How might you modify your distiller so that it works well using only sunlight?