Gelatin is the substance that makes Jell-O jiggle. See what happens when food coloring molecules move, or DIFFUSE through Jell-O.
This creative science experiment that my kids and I invented lets you play with floatation physics by sprinkling glitter on melted gelatin, watch colorful dyes diffuse to create patterns and then use cookie cutters to punch out sticky window decorations. Water will evaporate from the gelatin, leaving you with paper-thin “stained glass” shapes.
-plain, unflavored gelatin from the grocery store or Target
–a drinking straw
*You can use the recipe below for two pans around 8×12 inches, or use large, rimmed cookie sheets for your gelatin. For a single pan, cut the recipe in half.
Step 1. Add 6 packs of plain, unflavored gelatin (1 oz or 28 gm) to 4 cups of boiling water. Stir well until all the gelatin has dissolved and remove bubbles with a spoon.
Step 2. Allow gelatin to cool to a kid-safe temperature. Pour the liquid gelatin into two large pans so it’s around 1-1.5 cm deep. It doesn’t have to be exact.
Step 5. In the pan with no glitter, use a straw to create holes in the gelatin, a few cm apart, scattered across the surface. It works best to poke a straw straight into the gelatin, but not all the way to the bottom. Spin the straw and remove it. Then, use a toothpick or skewer to pull out the gelatin plug you’ve created. This will leave a perfect hole for the food coloring. Very young children may need help.
Step 6. Add a drop of food coloring to each hole in the gelatin.
Step 7. Let the gelatin pans sit for 24 hours. Every so often, use a ruler to measure the circle of food coloring molecules as they diffuse (move) into the gelatin around them (read about diffusion at the bottom of this post.) How many cm per hour is the color diffusing? Do some colors diffuse faster than others? If you put one pan in the refrigerator and an identical one at room temperature, does the food coloring diffuse at the same rate?
Step 8. When the food coloring has made colorful circles in the gelatin, use cookie cutters to cut shapes from both pans of gelatin (glitter and food coloring), carefully remove them from the pan with a spatula or your fingers, and use them to decorate a window. (Ask a parent first, since some glitter may find its way to the floor!) Don’t get frustrated if they break, since you can stick them back together on the window.
Step 9. Observe your window jellies each day to see what happens when the water evaporates from the gelatin.
When they’re dry, peel them off the window. Are they thinner than when you started? Why? Can you re-hydrate them by soaking the dried shapes in water?
The Science Behind the Fun:
Imagine half a box filled with red balls and the other half filled with yellow ones. If you set the box on something that vibrates, the balls will move around randomly, until the red and yellow balls are evenly mixed up.
Scientists call this process, when molecules move from areas of high concentration, where there are lots of other similar molecules, to areas of low concentration, where there are fewer similar molecules DIFFUSION. When the molecules are evenly spread throughout the space, it is called EQUILIBRIUM.
Lots of things can affect how fast molecules diffuse, including temperature. When molecules are heated up, they vibrate faster and move around faster, which helps them reach equilibrium more quickly than they would if it were cold. Diffusion takes place in gases like air, liquids like water, and even solids (semiconductors for computers are made by diffusing elements into one another.)
Think about the way pollutants move from one place to another through air, water and even soil. Or consider how bacteria are able to take up the substances they need to thrive. Your body has to transfer oxygen, carbon dioxide and water by processes involving diffusion as well.
Why does glitter float on gelatin? An object’s density and it’s shape help determine its buoyancy, or whether it will float or sink. Density is an object’s mass (loosely defined as its weight) divided by its volume (how much space it takes up.) A famous scientist named Archimedes discovered that any floating object displaces its own weight of fluid. Boats have to be designed in shapes that will displace, or push, at least as much water as they weigh in order to float.
For example, a 100 pound block of metal won’t move much water out of the way, and sinks fast since it’s denser than water. However , a 100 pound block of metal reshaped into a boat pushes more water out of the way and will float if you design it well!
What is the shape of your glitter? Does it float or sink in the gelatin?
Here’s a video I made for KidScience app that demonstrates how to make window gellies
Credit: My 11 YO daughter came up with the brilliant idea to stick this experiment on windows. I was just going to dry out the gelatin shapes to make ornaments. Kids are often way more creative than adults!
Want to take egg-dying up a notch the easy way? Marbling eggs using whipped cream and food coloring is a great project for little ones and the results are downright gorgeous!
Hint: Wear disposable glove to prevent your fingers from getting stained.
-hard boiled eggs
-a shallow container
-cool whip or whipped cream
-food coloring (neon, if you can get it)
-a chopstick or toothpick
1. Soak eggs in vinegar for 5 minutes.
2. Spread and smooth a layer of whipped cream across the bottom of the container and drip food coloring all over the whipped cream.
3. Swirl the drips into patterns using a toothpick or chopstick.
4. Remove eggs from vinegar, blot them with a paper towel and roll them through the food coloring. Put them on a plate to dry.
5. When the eggs are dry, wipe the excess whipped cream and color from the shells.
The science behind the fun: Food coloring is an acid dye, so the vinegar (acetic acid) helps it form chemical bonds with the egg shell, dying the egg.
Remember this homemade snow candy from Laura Ingalls Wilder’s classic “Little House in the Big Woods?” You can make the same amazing maple treats using heat evaporation and quick cooling in the snow, or on crushed ice cubes.
Here’s how to make the candy, along with some candy-making science, straight from the pages of my new book, “Outdoor Science Lab for Kids,” which you can order from your favorite book retailer by clicking here.
-1 cup pure maple syrup
-fresh, clean snow
Safety Tips and Hints:
-Hot sugar syrup can cause burns. This experiment must be done with adult supervision.
-Allow candy to cool completely before tasting.
-Only use pure maple syrup for the best results.
Step 1: Go outside and scout out a spot with some clean snow several inches deep for making your candy. Alternately, collect and pack down a few inches of fresh snow in a large, flat container, like a casserole dish. (You can use crushed ice cubes if you don’t have snow.)
Step 2. Boil the maple syrup in saucepan, stirring constantly until it reaches around 235-240 degrees F (soft ball stage.)
Step 3. Remove the maple syrup from the heat and carefully pour it into a heat-resistant container with a spout, like a Pyrex measuring cup.
Step 4. Pour wiggly candy lines into the snow to freeze them into shape.
Step 5. When you’re done, remove the candy from the snow with a fork.
Step 6. Eat your candy right away, or let it warm up and wind it around sticks or skewers to make maple lollipops. Enjoy!
The Science Behind the Fun:
Maple syrup is made from watery tree sap boiled to evaporate most of the moisture it contains when it’s first tapped from a tree. Following evaporation, the syrup that remains is mostly made up of a sugar called sucrose, but it also contains smaller amounts of glucose and fructose.
Naturally, other organic compounds are also present in tree sap, giving syrup from different areas unique flavors. Syrup collected earlier in spring when it is cold tend to be light in color and have a mild flavor. As the days get warmer, microbes ferment some of the sugar in the syrup, making it darker and giving it a more robust taste.
In this experiment, you heat maple syrup, evaporating even more water. A super saturated solution forms, which holds more sugar molecules in the liquid than would be possible if you evaporated the water at room temperature.
When you pour the supersaturated sugar into the snow, it cools quickly, forming some sugar crystals to give the maple candy a soft, semi-solid consistency. Heating the syrup to a higher temperature will evaporate more water, resulting in even more crystal formation in the cooled syrup, making it harder to bite. If you carefully evaporate all of the water from maple syrup, you’ll be left with pure maple sugar crystals.
-Try collecting some syrup from your pan at several different temperatures and compare the resulting snow candy for texture, color and consistency.
-Can you do the same experiment with other sugar syrups, like molasses or corn syrup?
-Try to make maple sugar.
Crying over broken candy canes? Cry no more. Make art!
My publisher recently sent me a copy of “Amazing (Mostly) Edible Science,” by Andrew Schloss. There are tons of fun experiments in the book, but Candy Cane Origami seemed like a perfect one to try during the holidays.
*Melted candy can get dangerously hot, so parental supervision is required!
-candy canes (broken or whole), wrappers removed
-heavy-duty aluminum foil
-a cookie sheet
-a wire cooling rack
What to do:
- Preheat oven to 250F.
- Cover cookie sheet with foil
- Place candy canes on foil, not touching each other
- Bake candy canes for around 10 minutes and have an adult check them. They should be stretchy, but not too hot to touch.
- When the candy canes are ready, bend, fold, twist and pull them into cool shapes. Try pulling one long and wrapping it around a chopstick to make a spiral. What else could you try?
- If the candy gets to brittle to work with, put it back in the oven for a few minutes to make it soft again.
The science behind the fun:
If you looks at the ingredients of candy canes, they’re usually made of table sugar (sucrose), corn syrup, flavoring, and food coloring. Glucose and fructose are sweet-tasting molecules that stick together to make up most of the sugars we eat, like table sugar (sucrose) and corn syrup. You can think of them as the building blocks of candy.
At room temperature, candy canes are hard and brittle, but adding heat changes the way the molecules behave. Both table sugar and corn syrup contain linked molecules of glucose and fructose, but corn syrup has much more fructose than glucose, and the fructose interferes with sugar crystal formation. According to Andrew Schloss, “the corn syrup has more fructose, which means the sugar crystals in the candy don’t fit tightly together. The crystals have space between them, which allows them to bend and move without cracking.”
Here’s a great article on the science of candy-making!
Spring is egg season. You may prefer dyed eggs, hard-boiled eggs, deviled eggs, or even dinosaur eggs. No matter what kind of eggs you like best, you’ll love these eggsperiments that let you play with the amazing architecture of eggs, dissolve their shells and even dye them with the pigments found in your refrigerator. Just click on experiments for directions and the science behind the fun!
Brrr. It’s really cold here in Minnesota. Perfect for making ice lanterns by filling balloons with water and setting them outside the back door. I had a great time talking ice lanterns and homemade ice cream (an edible experiment in my new book) on WCCO MidMorning this AM. As promised, here’s the recipe for “Ice Cream Keep Away.” After all, it’s never to cold to eat ice cream.
Ice Cream Keep Away (from Outdoor Science Lab for Kids- Quarry Books 2015)
- – 2 cups milk
- – 2 cups heavy cream
- – ½ cup sugar
- – 2 Tbs. vanilla
- – quart or pint-sized plastic zipper freezer bags
- – gallon-sized zipper freezer bags
- – 2 cups of rock salt or table salt
- -large bag of ice
- -dish towels
Safety Tips and Hints
- If the ice cream isn’t frozen when you check it, add more ice and salt to the outer bag and continue to throw it around for another five or ten minutes.
- You make enough ice cream mix in this lab to make 4 ice cream footballs at a time, so there’s plenty of ice cream and fun to go around!
Step 1: Make an ice cream mixture by combining 2 cups milk, 2 cups cream, ½ cup sugar and 2 Tbs. vanilla to a bowl and mix well.
Step 2. Add one cup of ice cream mixture to a quart or pint-sized freezer bag, squeeze out some of the air and zip it closed.
Step 3. Place the small bag of ice cream mixture in a second small bag, squeeze out the air and zip it closed as well.
Step 4. Place the double-bagged ice cream mixture into a gallon-sized bag and fill the larger back with ice.
Step 5. Pour a generous ½ cup of salt over the ice in the bag and zip the bag shut.
Step 6. Wrap a dish towel around the bag of ice and place it in a second gallon bag. Zip the outer bag closed.
Step 7. Play catch with the bag of ice and ice cream for ten or fifteen minutes.
Step 8. Remove the bag of ice cream mix from the outer bag and enjoy your frozen treat.
The Science Behind the Fun:
Making ice cream is a lesson in heat transfer and crystallization.
Water is the solid form of ice. When you add salt to ice, it lowers the freezing temperature of the water, melting it and allowing it to remain a liquid far below water’s normal freezing temperature of 32 degrees F (O degrees Celsius.)
In this lab, adding salt melts the ice, making a really, really cold ice-salt-water mix. The icy salt water pulls, or transfers, heat out of the ice cream mixture, freezing the water molecules in the milk and cream into ice crystals.
Depending on how fast ice cream freezes and what ingredients it contains, the ice crystals will be different sizes. If you freeze the mixture very fast, you will probably get big ice crystals that make the ice cream grainy. Ingredients like gelatin encourage smaller crystals to form, making smoother frozen treats. Adding emulsifiers like eggs to the mix helps the fats and water combine better, creating ice cream that thaws more slowly.
- Try added less salt to the ice to freeze the ice cream more slowly. How does this change the texture of the final product?
- What happens if you add a Tbs. of gelatin to the mix?
Did you know you can use science to make amazing works of art in Jell-O? I created this experiment to make Star Wars Jell-O, but you can take it in whatever direction you want. Remember, you’ll need agar, lots of Jell-O and some coconut milk to start experimenting! If your agar figures break, you can fill in the cracks with more melted agar! I ordered the silicone Star Wars molds on Amazon.com.
Here’s the science part: Agar is a substance extracted from the cell walls of red algae. It’s often used in cooking and science experiments. Agar has a higher melting temperature than the gelatin used to make Jell-O. So, if you put a piece of agar gel into melted Jell-O, the agar won’t melt unless the Jell-O is really hot (about 150 degrees Fahrenheit or 65 degrees Celsius!) That means you can create works of agar art to embed in your favorite Jell-O. We used silicone molds, cookie cutters and a molecular gastronomy technique called oil spherification to make our agar decorations. To make the orbs using spherification, you simple drip coconut milk agar through cold oil, forming perfect spheres that solidify as they fall. We talked with Astronaut Abby on Kare11 Sunrise about how you could make these orbs in space. Click here to see the segment.
Vegetarians like to eat agar, since it’s made from algae and not animals. In labs, scientists use agar to make petri dishes for growing microorganisms, since it won’t melt at high temperatures in incubators. They also use it to make gels for electrophoresis, to separate DNA and RNA molecules by size!
*If you want to make white orbs from the coconut milk agar, you’ll need to plan ahead and chill tall jar or glass of vegetable oil in the freezer until it is thick and almost frozen. You’ll also need some squeeze bottles or clean eyedroppers.
Coconut Milk Agar -To create your white decorations and mini orbs, mix up this coconut milk agar dessert.
2 1/2 cups water
4 Tbs Agar flakes from Asian section of grocery store or COOP
1 cup coconut milk (not lowfat) Mix the coconut milk well before you measure it.
4 Tbs. sugar
In a sauce pan or the microwave, heat 4 Tbs. agar in 2 and 1/2 cups water until the agar is completely dissolved. Adult supervision required.
To the agar mixture, add 1 cup coconut milk and 4 Tbs. sugar. Mix Well. Pour into molds, pour into a pan to cut shapes out with cookie cutters, or pour some into a squeeze bottle to make white orbs.
Coconut Milk Orbs (optional cool science experiment
Slowly drip melted coconut milk agar (above) through ice-cold vegetable oil. As it fall through the oil, it should harden and form orbs. Collect the orbs with a slotted spoon and rinse before adding to your Jell-O.
Follow the directions on the package for the speed set method. If you make a double batch, pour half of it into the bottom of a large, glass casserole dish or bowl. If it’s a single batch, pour the whole thing in. If you made coconut milk orbs, put some in the melted Jell-O to see whether they float or sink. Let the Jell-O solidify and arrange your agar decorations on the Jell-O.
Make or remelt more Jell-O. When it’s cooled down a bit, pour it over your decorations to trap them in the Jell-O. You may want to leave them sticking out a little, or cover them completely with Jell-O over them for effect.
What else could you try? What Jell-O masterpiece can you create?
Molecules move from areas of high concentration, where there are lots of other similar molecules, to areas of low concentration, where there are fewer similar molecules in a process called DIFFUSION. When the molecules are evenly spread throughout the space, they have achieved EQUILIBRIUM.
Lots of things can affect how fast molecules diffuse, including temperature. When molecules are heated up, they vibrate faster and move around faster, which helps them reach equilibrium more quickly than they would if it were cold. Diffusion takes place in gases like air, liquids like water, and even solids.
You can watch food coloring molecules diffuse into gelatin (a colloid) when you do this fun, edible Halloween experiment.
Dissolve two 3oz packages of lemon Jell-O in 1 and 1/4 cups of boiling water. (Adult supervision required.) Allow it to cool briefly, and pour it into 2 ice-cube trays with oval-shaped holes. Refrigerate until firm.
Dissolve one 6oz package of Berry Blue Jell-O in 1 and 1/4 cups of boiling water. Cool briefly.
Using the end of a potato peeler or a strawberry corer to hollow out a circle in the middle of each yellow Jell-O “eyeball.” Carve the circle about halfway to the bottom of the gelatin. Use a toothpick or skewer to remove the Jell-O.
Fill the hollow with melted blue gelatin and return to the refrigerator to harden. The blue Jell-O will be the pupil of the eye.
Set ice cube trays containing Jell-O in a casserole dish of hot tap water for 1-2 minutes. Turn upside down in another dish to un-mold and then move your eyeballs to another serving dish.
Use a straw to add Kool-Aid liquid (like Cherry) to the center of each eyeball. Then, use a sharp skewer to draw lines out from the center.
Cover with plastic wrap and let sit for a few hours so the Kool-Aid will start to diffuse.
Add a second color Kool-Aid drops (Like Blue Raspberry) to the center of the eye and repeat.
Cover and refrigerate until ready to serve. The Kool-Aid colors will continue to diffuse into the eyeballs!
I’ve been having fun with fermentation the last few weeks and my kids loved making root beer. In a week or two, I’ll post instructions, but here’s a general how-to demo I did on WCCO MidMorning.
My 8-YO loves Orbeez, those water-thirsty polymer balls that go from the size of cookie sprinkles to the size of marbles after a quick soak.
I wondered whether we could make something similar from gelatin or agar.
A quick search online showed me that some chefs use a technique called oil spherification to make tiny round morsels using everything from balsamic vinegar to fruit juice, mixed with gelatin and agar. It’s known to cooks as a “molecular gastronomy” technique, and takes advantage of the fact that water and oil don’t mix. Water-based droplets falling through chilled oil form into perfect spheres due to surface tension, and gelatin and agar added to the mix are colloids that solidify as they cool.
We made some fun (inedible) orbs of our own, using the technique: standard orbs (from gelatin or agar and water), floating orbs (with agar and vinegar) and color-changing acid/base indicator orbs (from red cabbage juice and gelatin or agar.) Adult supervision is required for this project, since it involves hot liquids. The orbs may also be a choking hazard, so keep them away from toddlers. I demonstrated how to make them on Kare11 Sunrise News.
To make magic orbs, you’ll need
-unflavored gelatin or agar*
-cold vegetable oil in a tall container. Chill oil in freezer or on ice for at least an hour, or until it is cloudy, but still liquid.
HINT: Orbs made with vinegar and agar shrink better than those made with gelatin (see floating orb recipe below!)
Standard colored orbs:
1. With adult supervision, dissolve 5 packets unflavored gelatin or 2 Tbs. agar in 1 cup hot water. Add 2 tsp. vinegar. Microwave and stir until completely dissolved.
2. Pour into smaller containers and add food coloring. When cooler, but not solid, add the melted, colored gelatin or agar to an empty glue container or squeeze bottle.
3. Drip gelatin or agar solution into the cold oil, a few drops at a time so it forms into marble-sized orbs and sinks. Drip two colors together to make multi-colored orbs! Allow to cool for 30 seconds or so and retrieve with a slotted spoon or strainer. Rinse with water and repeat, re-chilling the oil as needed until you have as many orbs as you want.
4. Rinse orbs with water. Dry them out by setting them on a plate overnight if you want to see them shrink and then re-hydrate them with water. Orbs can be kept in a plastic bag in the refrigerator. (Keep away from small children, since they may be a choking hazard.)
To make floating orbs, follow directions above, but make with 1 cup white vinegar and 2 Tbs. agar. They will sink and float when added to water with a few tsp. of baking soda mixed in as the vinegar and baking soda react to form carbon dioxide gas.
To make color-changing orbs, dissolve 2 Tbs. agar or 5 packs unflavored gelatin in 1 cup red cabbage juice (magic potion) and follow directions for making orbs. Then drop them in vinegar to watch them turn pink or in water containing baking soda to watch them turn blue!
Could you make homemade jelly beans using flavored gelatin using this same method? Try it!
*Agar, or agar agar flakes can be found in the Asian food section of many grocery stores!