Gather materials: 3% hydrogen peroxide (enough for a few cups), dry yeast, warm water, dish soap, food coloring (optional), baking soda (optional), yeast activator container, large tray or baking sheet, funnel (optional), measuring cups/spoons, gloves, safety goggles
Set up a safe workspace: clear the area, place the tray on a stable surface, wear gloves and safety goggles
Add hydrogen peroxide to the container: pour 3% hydrogen peroxide into the tray/container
Add dish soap: squeeze in dish soap and gently swirl to mix without splashing
Add food coloring (optional): add a few drops and gently mix
Prepare yeast activation: in a separate cup, mix warm water with dry yeast (optionally add a pinch of baking soda) and stir
Pour the activated yeast mixture into the hydrogen peroxide setup quickly
Step back and allow the foam to grow
Stop/clean up: once reaction slows, rinse with plenty of water and dispose of materials per local guidance
Keep unused chemicals capped and stored safely away from heat and children