Make Ectoplasm Slime for Halloween

Ectoplasm Slime
Ectoplasm Slime (Anne Helmenstine)

If you’re familiar with the Ghostbusters movies, you know about ectoplasm and ghosts. It’s the viscous supernatural goo associated with spirits manifesting in the living world. Unless you have a pet poltergeist, you’ll need to make your own ectoplasm for haunted houses and ghoul costumes. Fortunately, all it takes is a simple twist on an edible slime recipe to make the stuff:

Ectoplasm Slime Ingredients

  • 1 cup (8 ounces) water
  • 1 teaspoon soluble fiber (e.g., Metamucil)
  • food coloring (optional)

Fiber comes in both flavored and unflavored versions. The ectoplasm shown in the photo was made using orange Metamucil, with a drop of neon green food coloring. It’s orange flavored and minimally mixed to give a mottled color. I liked the flavor and found the color extra gross and creepy. However, I don’t know for sure whether ectoplasm even has a color (fairly sure it doesn’t taste like oranges), so I can’t speak for its realism. You could always opt for unflavored, uncolored slime. That kind of looks like snot… ¬†whatever floats your boat.

Let’s Make Ectoplasm!

If you don't add coloring, your slime will be ghostly and transparent.  (Steve Jurvetson)
If you don’t add coloring, your slime will be ghostly and transparent. (Steve Jurvetson)
  1. In a microwave-safe bowl, stir together the fiber and water.
  2. Microwave the mixture on high power for 3 minutes.
  3. Stir your ectoplasm and then heat it on high for another 3 minutes.
  4. Check the consistency of the slime. If it is too liquid-y, microwave it for another minute, check it, and then either call it good or continue cooking for 1-3 minutes until you get the consistency you want.
  5. Add a drop or two of food coloring. You can mix in the color completely, or not, depending on the desired appearance.
  6. If you aren’t using the ectoplasm right away, it can be stored in a sealed bag or container in the refrigerator up to a week before use. It will¬†last even longer for decorating purposes, though I wouldn’t want to eat it past that point.


You can make glowing ectoplasm by stirring in a bit of glow paint or ectoplasm that glows under a black light by adding ink from a fluorescent highlighter pen. These variations are way cool, but not edible, so they should be used on surfaces or dripping from clothes, not around your eyes or mouth.

More Slime Recipes To Try