This creepy edible green goo is essentially homemade lime gel frosting, which means it can be used as a fun prop for Halloween desserts and mixed drinks.

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Top down view of syringes filled with edible green goo in a beaker.

About Edible Green Goo

Halloween is the absolute best time of the year to go all out with creepy and fun treats, and this unique edible green goo is bound to add some shock value to your next spooky spread.

Plus, this slimy treat can easily fit with a variety of different scary themes, from an unhinged doctor’s lab to messy, oozing ghosts.

Edible green goo in syringes and beakers on a tray.

What’s in edible green goo?

While this recipe may have the oozy look and texture of slime, it’s essentially a recipe for homemade gel frosting that’s a tad more watery than normal.

To make it, you’ll need:

  • Cold water and cornstarch – You’ll make a slurry with this, which is what helps thicken the mixture to be slime-like.
  • Light corn syrup – Adds sweetness and helps thicken.
  • Lime juice and lime zest – To give the a lime goo flavor that matches the green color.
  • Green gel food coloring – To give it the right color. The lime ingredients don’t provide enough color on their own without it (it would be a faint yellow color otherwise) so the food coloring is needed to get the right presentation.
Close up of two syringes laid on their side filled with edible green goo.

How to use this for Halloween

No matter what your plans on for Halloween, this edible green ooze would an ideal way to showcase spooky slime or a creepy doctor theme.

To give you some ideas, try:

  • Adding it to syringes and beakers, as pictured.
  • Used as a slime topping on cupcakes. You could even serve the cupcakes with mini syringes so guests can deliver a their own “shot” of goo on or inside the cupcakes.
  • Coating drink glasses or rims.
  • Serve goo like a dip that guests can dip other treats into, like cake or marshmallow pops.
  • Create a “spooky salad” by using the goo as a dressing mixed with other fun treats, like candy eyes, marshmallows, etc. Serve this in small portions because it’s bound to be very sweet.

Where do you get the props?

If you’d like to do a mad scientist theme like the one pictured, you’ll need to pick up:

  • Syringes – Each one holds about 1 1/2 tablespoons of slime.
  • Beakers – This will give you a full set of different items to mix and match with.

Can you make it another color?

Technically, yes you can! This fun Halloween treat gets most of it’s color from the green gel food coloring. However, keep in mind that no matter what color you make the goo, it will have a lime flavor (unless you adjust that, too).

Squeezing a syringe to squeeze out a drop of edible green goo.

How many limes do you need?

This recipe calls for both lime juice and lime zest. You should be able to everything you need from a single medium-sized lime.

How long does this green goo last?

Once prepared, this edible treat can be stored in a sealed container in the refrigerator for up to one week. Bring the goo back to room temperature before serving.

Notes & tips for edible green goo

  • Once prepared, be careful when handling this edible goo; it can easily stain hands, clothes, and surfaces.

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How to make edible green goo

This next part is only a photo tutorial of the recipe steps. If you’re looking for the full recipe measurements and instructions, scroll down to Recipe Details.

Step 1 – To kick things off, start by creating a slurry. In a small bowl, whisk together the cold water and cornstarch, then set it nearby.

Step 2 – In a small saucepan, add the light corn syrup, the slurry you just made, lime juice, lime zest, and green gel food coloring. Bring the mixture to a simmer over medium heat, then cook for 30 seconds while whisking constantly.

Step 3 – Remove the saucepan from heat and allow the liquid to cool completely.

Step 4 – Use the green goo in fun Halloween props like syringes or beakers.

Step 5 – Serve and enjoy!

Recipe Details

Top down view of syringes filled with edible green goo in a beaker.
5 from 1 vote

Edible Green Goo

5 minutes prep + 5 minutes cook
163 kcal
Yields: 6 servings (1 1/3 tbsp per)
This creepy edible green goo is essentially homemade lime gel frosting, which means it can be used as a fun prop for Halloween desserts and mixed drinks.



  • In a small bowl, whisk together cold water and cornstarch to form a slurry.
  • In a small saucepan over medium heat, add cornstarch, lime juice, lime zest, greel gel food coloring, and prepared slurry. Bring to a simmer and then cook, whisking constantly, for 30 seconds.
  • Remove saucepan from heat and allow to cool to room temperature.
  • Serve immediately in beakers, syringes, or other Halloween props.


Recipe makes roughly 1 cup edible green goo. Serving size is based on how much goo would fit in a 20 ml syringe, which is about 1 1/3 tablespoons.


Serving: 1serving | Calories: 163kcal | Carbohydrates: 44g | Protein: 1g | Fat: 1g | Sodium: 35mg | Potassium: 4mg | Fiber: 1g | Sugar: 44g | Vitamin A: 1IU | Vitamin C: 1mg | Calcium: 8mg | Iron: 1mg

I do my best to provide nutrition information, but please keep in mind that I’m not a certified nutritionist. Any nutritional information discussed or disclosed in this post should only be seen as my best amateur estimates of the correct values.

Author: Chrisy