Homemade pop rocks aren’t as fizzy as the ones you buy at the store, but they’re mighty tasty! Citric acid combines with baking soda to make carbon dioxide gas bubbles that get trapped in the candy. Adding extra citric acid and baking soda to the surface of the candy gives some extra fizz when you put them in your mouth. Trick your friends by adding a flavor that doesn’t match the color!
Warning: Ages 8 and up only. Extremely hot candy syrup. Adult supervision required.
2 cups sugar
1/4 cup water
1/2 cup corn syrup
a few drops of food coloring
1 tsp flavoring, like orange or cherry
1/4 cup citric acid + 1 tsp to sprinkle on in final step
1 tsp baking soda plus some to sprinkle on the candy
Step 1. Coat a the bottom of an inverted baking sheet with cornstarch.
Step 2. Boil sugar, corn syrup, and water, stirring until it reaches 300 degrees F.
Step 3. Remove the hot, melted candy from heat. Stir in food coloring, flavoring, 1/4 cup citric acid and 1 tsp baking soda.
Step 4. Very carefully, pour the mixture onto the baking sheet. Do not touch!!! Sprinkle 1 tsp. citric acid evenly over the surface of the candy.
Step 5. Let the mixture cool for at least 30 minutes and the break it into small pieces. Put some of the fragments in a plastic zip lock bag and use a hammer or rolling pin to crush them into tiny pieces or powder.
Step 6. Sprinkle on a little more baking soda and shake up in the bag.
Step 7. Enjoy the leprechaun pop rocks!
Does hand-washing really get rid of germs? Yes! Scrubbing your hands with soap and water for the length of time it takes you to recite the ABC’s will get rid of the majority of harmful microbes on your hands.
Here’s a video on how to make Petri plates for a hand-washing experiment, where you touch labeled sections of the plates with your fingertips before washing, after washing with water alone, and after scrubbing with soap or hand sanitizer. You can also use the plates to swab and grow microbes from around your house or school!
Find the recipe for Petri Plates in my book Kitchen Science Lab for Kids, or click here for a link to the recipe on my original blog post, where you can also read more about the science!
Most clear hard candy has what scientists call a glass structure. It’s a disorganized jumble of three kinds of sugar: glucose, fructose and sucrose, which can’t assemble into organized crystals, so it remains transparent when you melt it and allow it to re-harden.
To make stained glass for our gingerbread house windows, I adapted the crushed stained glass candy project from my book “STEAM Lab for Kids.” The challenge was figuring out how to create perfect rectangles. After some trial and error, I discovered that scoring the candy when it was still warm and soft created weak points, which allowed me to snap the candy into clean shapes once it had hardened.
-Jolly Ranchers, Life Savers or another clear, hard candy
-a baking sheet (spray or grease the baking sheet, if not using a silicon liner)
-a silicon liner for the baking sheet, if you have one
-a metal spatula or dough scraper
Safety tip: Adult supervision recommended. Hot, melted candy can cause burns. Don’t touch it until it has cooled.
What to do:
- Pre-heat the oven to 350F.
- Unwrap the candy and arrange the pieces on a baking sheet so that they’re close together, but not touching.
- Bake the candy for 7 to 8 minutes, or until it has melted.
- Remove the candy from the oven. Tilt the baking sheet, if needed, to fill gaps.
- Use the spatula to score (make lines in) the candy, creating whatever shapes/sizes you need.
- When the candy has cooled, snap it carefully along the lines you made. (See photo at the top of this post.)
- Eat your creations, or use them to decorate some edible architecture.
- Try crushing the candy before you melt it for different visual effects. What else could you try?
Use science to make your holidays shine! Here are a few fun ornaments adapted from projects in my book “STEAM Lab for Kids.” Basic instructions can be found below. Buy your own copy of “STEAM Lab for Kids” anywhere books are sold to learn more about the “Science Behind the Fun!” Happy Holidays!
LED Ornaments and Jar Globes:
To make LED ornaments, buy plastic jars or ornaments with removable bases. Use sculpting clay (the kind that won’t harden) to design a scene and add LEDs connected to a coin-cell battery to light your creation. LEDs can be ordered online. See images below.
Epsom Salt Crystal Ornaments:
(Warning: Hot liquids require adult supervision.) To make the Epsom Salt crystals, dissolve 3 cups of Epsom salts in 2 cups of water by heating and stirring until no more crystals are visible. This creates a supersaturated solution. Allow the solution to cool slightly. Hang pipe cleaners formed into snowflakes in jars or hollow ornaments and pour the solution in. When long, needle-like crystals have formed, remove the pipe cleaners from the jars. You can leave them in the ornaments, and drain the liquid.
To make a holidays version of the fizzing bath tablets in the video, we scented them with pumpkin pie spice and added a little more oil to incorporate the extra ingredients.
1 cup baking soda
¼ cup cream of tartar
3 Tbsp. coconut oil, melted to liquid
1 tsp. pumpkin spices
-Whisk together baking soda, cream of tartar and pumpkin spices. Slowly drizzle in coconut oil, mixing immediately. Stir for several minutes until you get a nice even mixture that holds together when you press it between your fingers. Add a little more oil if it is too powdery.
-Add a few drops of food coloring and mix again until the color is incorporated.
-Press the bath bomb mixture into a tablespoon and tap in on a tray to remove the bath tablet. If they don’t hold together, try adding a little more oil and mixing again. Dry the bath fizzies on a plate or cooking sheet and package them in cellophane bags or pretty baking cups for friends and family. Use the fizz bombs within a few weeks for maximum fizziness!
You can make larger “bath bombs” using molds for round ice cubes (which we found at Target.) Double or triple the recipes, gently press some mixture into each side of the mold, and mound a little extra on each side. Press the mold together to compress the bath bomb mixture into a single ball. Tap one side gently with the back of a spoon and gently open the mold to release that side of the sphere. Hold it in your palm and repeat with the other side to release the entire bath bomb from the mold.
The science behind the fun: The chemical name for baking soda is sodium bicarbonate , and cream of tartar is an acid called potassium bitartrate, or potassium hydrogen tartrate . When you mix them together in water, you create a chemical reaction that forms carbon dioxide gas bubbles! It’s interesting to note that at temperatures below 76 degrees F (25 C), coconut oil is a solid, but that at temperatures above this, it melts into a clear liquid. How does this affect your bath fizzies? Will they work in cold water as well as they do in warm water? Try it!
Eggs and sugar have great chemistry. Mix them together to create these sweet, crunch Halloween treats with a recipe from my upcoming book “Kitchen Science Lab for Kids: Edible Edition.“
They’ll take a few hours to bake, so plan ahead for this fun, edible science project.
Meringues are simply egg whites whipped into sugary foams. As you whip air into the mix, glue-like egg white proteins stick to the bubbles, stabilizing them to form a thick foam. The sugar you add combines with water from the eggs to form a sweet syrup.
When you bake meringue at a low temperature for a long period of time, the sugar and protein are transformed from an elastic goo to a glassy state, creating a crunch mouthful of bubbles.
Hard meringues are made using ¼ cup sugar per egg white, with a pinch of cream of tartar. Don’t skip the cream of tartar (an acid.) It helps stabilize the egg whites in the meringue.
To make Halloween Meringues, you’ll need:
3 egg whites from extra large eggs
1/8 tsp cream of tartar
¾ cup granulated sugar
1/4 tsp Vanilla
Food coloring (gel works best)
Sprinkles or dusting sugar (optional)
Stand mixer or hand mixer
2 baking sheets
Pastry bags or large plastic zipper bags with the corners cut off
Round piping tips for pastry bag, if you have them
1. Pre-heat oven to 200 degrees F.
2. Line two baking sheets with parchment paper.
3. Beat three egg whites on medium until they start to foam.
4. Add 1/8 tsp. cream of tartar and continue to beat the egg whites, increasing the speed to high.
5. When the foam gets thicker enough to form soft peaks, add 3/4 cup sugar, a tablespoon or so at a time as you beat the eggs. Add vanilla.
6. Continue beating the mixture until stiff, glossy peaks with rounded tips form. Don’t over-beat the meringue.
7. Add a round tip to the pastry or plastic bag. Fill the bag with the meringue you made.
8.Use the bag and tip to pipe half of the meringue into blobs. You can color it with food coloring before piping it, if you wish.
9. Make some colorful streaks on the meringues by using a toothpick to smear food coloring on the inside of the pastry tip before putting it in the bag and piping the meringue. A small tip can be used to create eyes for the blobs, snakes and worms, or you can use sprinkles and dusting sugar to decorate.
10. Bake the meringues for 1-2 hours, until they feel dry and let them cool.
Sound waves are formed when air molecules are compressed (pushed together), creating pressure waves.
It’s fun and easy to play with sound waves! Here are some ideas for you:
Have fun experimenting!
Combine science and art to engineer and decorate a custom water bottle jacket as unique as you are. Test different every-day insulators to see what works best to to keep water cold all day long!
-a washable plastic water bottle
-flexible insulating material, like craft foam, bubble wrap or fabric batting
-decorating materials, like stickers, ribbons or foam stickies
-a thermometer (optional)
-4 disposable empty water bottles or cans that are the same size (optional)
What to do:
(Optional) Test insulators by insulating each of the empty cans or bottles with different material. Fill each of them with the same amount of hot tap water and check the temperature of each periodically to see which material does the best job of slowing cooling of the water. The one that keeps water hot the longest is the best insulator, since it slows the movement of heat from one area to another.
Use the best insulator to build an insulating case for your water bottle. Make it big enough so that your bottle will slide out for washing. We used thick craft foam and covered it with adhesive craft foam. Shipping folders made of bubble wrap work well too! Here’s how we built ours…
Add some ice water to the bottle and you’re good to go! Just remove the jacket when you wash the bottle.
Hands-on science experiment books are a great way to ease kids back into creative learning!
I recently shared some of the fun, easy, inexpensive science project ideas from my two newest books, “STEAM Lab for Kids” and “Star Wars Maker Lab” with a group of teachers on Twin Cities Live. Check out the clip below to learn to make hoop gliders and grow gorgeous Epsom salt crystals!
You can find my books at your local library, or pick them up at your favorite online or bricks-and-mortar retailer!
Sodium alginate (Say it like you say algae!) is a substance found in the cell walls of brown algae, including seaweeds and kelp. Its rubbery, gel-like consistency may be important for the flexibility of seaweed, which gets tossed around on ocean waves.
Here on dry land, you can use sodium alginate to make edible balloon-like blobs that are liquid in the middle. We can thank scientists for this delicious project, since they discovered that a chemical reaction between sodium alginate and calcium causes the alginate to polymerize, or form a gel. In this experiment, the gel forms on the outside of a sodium alginate blob, where the chemical reaction is taking place. The inside of the blob remains liquid!
No heat is required for this experiment, making it safe and fun for all ages!
Sodium alginate and calcium lactate can be tricky to find at the grocery store, so you’ll probably have to order them online. But they’re not very expensive, and you’ll have lots of fun playing with them!
-a blender or hand blender (parental supervision required for small children)
-1/2 tsp sodium alginate
-2 tsp calcium lactate
-flavored drink drops, like Kool-Aid or Tang (optional)
-squeeze bottle or syringe for popping boba*
You can make these with juice, but if there is any calcium in the juice, you may end up with foam in your blender, since it may start to polymerize the sodium alginate when you blend it in.
- Add 1 and 1/2 cup water (or calcium-free juice) to the blender.
- To the water, add 1/2 tsp. sodium alginate.
- Blend for about a minute, and let rest for 15 or 20 minutes, or until the bubbles are gone.
- If you want to add flavor, divide the sodium alginate solution into small containers and stir in the flavor, like a squirt of Kool-Aid liquid.
- Add 4 cups of water to a clean, clear glass bowl or container.
- To the water, add 2 tsp. calcium lactate and mix until completely dissolved. This is your calcium lactate “bath.”
- To make edible water balloons, fill a spoon, like a tablespoon, with the sodium alginate solution, and slowly lower it down into the calcium lactate bath. You’ll see a gel begin to form. Gently turn the spoon so the sodium alginate falls off the spoon and into the calcium lactate.
- After about 30 seconds, you’ll be able to see a pale blob in the water. Leave it there for three or four minutes. You can make several edible balloons at once.
- When the blobs are ready, use a spoon to carefully remove them from the bath and put them in a clean bowl of water for a few seconds to rinse them off.
- Put your edible balloons on a plate and taste them. What do you think?
- *To make popping boba, add the fruit-flavored sodium alginate to a squeeze bottle or syringe. Drip the flavored sodium alginate into the calcium lactate as fairly large drops. It may take some practice to get uniform drops of the size you desire. When they’re solid enough to remove from the calcium lactate, rinse them gently and add them to your favorite drink. A small sieve works well for rinsing.
Now that you know how to polymerize sodium alginate with calcium, what else could you try? Can you make a foam in the blender? Can you make gummy worms in the bath using the rest of your sodium alginate solution? Can you invent something entirely new??? Try it!
Thank you to Andrew Schloss’s book Amazing (Mostly) Edible Science for the experiment inspiration! Adding the Kool-Aid and Tang drops to add a little flavor and color was our idea! (This blog post was first published on KitchenPantryScientist.com on May 3rd, 2016 and revised to add popping boba July 24th, 2018.)