Kitchen Chemistry: When Jello and Science Collide!

Recently, my husband signed me up for a monthly snack box subscription from Japan. Every box contained strange and wonderful delights from shrimp flavored snack chips to cotton candy with pop rocks! One of the most interesting snacks was this Create-Your-Own dolphin candy, which came with ocean character molds, a scenic ocean background, and all of the ingredients and tools we would need to put it together! Essentially, we were given chemistry in a box, and our result would be candy!

This particular candy was like a fast acting Jello. As we were eating our newly made candy, we started wondering… Just how does Jello work anyway? How does it keep its shape? How does it go from solid to liquid, and then to a solid again? We decided to do some research to find out, and of course, these questions led us to some pretty fun experiments in the process!

CC Steven Depolo

Jello is made primarily from the protein Collagen. Collagen is found in all animals and is used in muscles and tendons; a connective tissue that is both incredibly strong while also flexible. This protein is quite prevalent in humans accounting for as much as 1/3 of the protein mass of the human body!

Collagen Triple Helix CC Wikimedia

One of the reasons why it holds so well both in animal bodies and in food products is because of the way the protein molecules are structured. We’re all familiar with the double helix structures of DNA. Well, Collagen is shaped in a triple helix! With that added strength, it’s no wonder those connective tissues are so strong!

When we make Jello, adding the hot water breaks apart those triple helices. As the solution cools, they reform, grabbing extra particles and water molecules, tightly locking them in place! In fact, those tightly trapped water molecules are what make jello jiggle! It’s essentially a liquid trapped within a solid!

Alright, so now we knew how jello works; it’s time for an experiment! We bought two different types of jello, sugar-free and regular. We wanted to know, if we put a variety of fruits in both types of jello, would they all set the same? If we wanted to make a jello fruit salad, would all fruits be equal?

Katie hypothesized that the acidity of certain fruits would prevent the jello from setting equally. So, in order to test this out, we needed to find the acidity of our fruits! To do this, we turned out our trusty homemade pH indicator!

Red Cabbage pH Test!

Materials Needed:

2 cups red cabbage finely chopped
Large temperature safe bowl
Boiling water (enough to cover your cabbage)
Clear plastic cups
A variety of liquids or foods to test!


1. Bring a large pot of water to a boil.

While waiting on the water, chop approximately 2 cups of purple/red cabbage into small pieces.

Put your cabbage into your bowl. When the water is done boiling, carefully pour it over the cabbage submerging as much of it as possible.

Wait 10 minutes.

By now your liquid should be a dark bluish color. Pour this through the strainer, into another easy to pour glass (like a large measuring cup).

Pour the liquid into your clear plastic cups. Set them up side by side. You also might want to make  a note of which substance will be tested in each cup, so you can keep track of your variables!

Add your variables! Pour one different liquid into each cup. You should begin to notice an immediate color change!

When you’re finished testing your liquids, match the colors up to this pH scale to see how acidic or basic your variables are!

Refer to this scale when testing your liquids! The lower the number, the higher the acidity. The higher the number, the more alkaline your liquids are!

Now that we knew the acidity of our fruits, it was time to put them to the test! Would the acidity have an effect on how well the jello sets? With the power of the scientific method, we were about to find out!


Materials Needed:

Note: This experiment requires a 2-3 hour time frame
Sugar-free Jello
Regular Jello
2 pieces each of a variety of fruits. We used strawberries, watermelon, bananas, apples, pineapples, and plums.
2 plastic or silicone ice trays
Note: This post contains affiliate links to products.



1. Chop all of your fruits into 1/2 inch cubes. Drop a piece (or more) into each ice tray.

Prepare both boxes of Jello by following the regular instructions on the package.

Pour the liquid Jello mixtures over your fruit. If the sugar-free and regular Jello are the same flavor, mark one of the ice trays so you’ll know which is which when you’re finished.

Following the instructions on your Jello packages, refrigerate the Jello for 2-3 hours.

Remove the Jello from the ice trays and examine the results!

When we examined the Jello, it became clear that the acidity did indeed have an effect on the Jello’s ability to set! In both samples, the pineapple didn’t set at all! This is because Pineapple, unlike many other fruits, contains an enzyme called bromelain, which actually breaks down the collagen into amino acids! It’s because it is broken down into its fundamental building blocks, that it can’t actually reform back into its triple helices when it cools!

We also found that other acidic fruits, such as strawberries, took much longer to set and had a fair bit of liquid remaining by the time we were done. The bananas and apples, however, had set more quickly than the rest of them. Interestingly, the sugar free Jello also set much faster than the regular Jello!
Well, we had set out to answer a question, and with our powers of science, we found our answers! However, in the process of researching for our experiment, we came across one more activity that we would like to try…


Now this is an AWESOME science experiment that only requires three things: gelatin, a balloon, and static electricity! When you combine these three ingredients, you get a sticky surprise that results in some really cool formations!

Materials Needed:

Unflavored Gelatin
Wool, Fleece, or a full head of hair


1. Inflate your balloon or go to your local grocery store and pick up a helium balloon!

2. Open your packet of unflavored gelatin and empty it onto a flat surface.

3. Charge your balloon with static electricity by rubbing it on your fabric, or your full head of hair! You’ll know when it’s ready by all of the hair sticking to your balloon!

4. Gently place your charged balloon over the gelatin. You’ll need to get really close, and you may need to lightly touch it. Once the gelatin clings to the balloon, slowly pull away to get your stalactites and stalagmites!

What’s happening?

As you rub your balloon, you’re actually knocking electrons off of the atoms on the balloon! This leaves positively charged ions, and they’re looking to balance themselves out. When you bring the charged balloon to the gelatin, it causes it to become positively charged too, which makes the particles cling together!

Note: For more experiments with static electricity, click here!


Turn this into an experiment by trying this with flavored gelatin as well as unflavored gelatin! We also experimented with different substances mixed in with the Jello. We tried salt, sugar, cardamom, baking soda, and rolled oats!

It was a lot of fun testing out different materials with our jello, and we learned a lot in the process! Of course for Katie, the best part about all of our experimenting, was eating the candy and Jello that resulted from it! I would say that I have to agree! Maybe the next time we get some crazy kind of candy in the mail, it might just lead to yet another round of experiments!

In the meantime, we’re going to keep having fun with our candy science and static electricity.

Happy Exploring!

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