Fizzy Heart Science Experiment

The kids are certain to love this Fizzy Heart Science Experiment! It’s a great way to get them excited and engaged in the learning process!

Looking for more like this? Check out these awesome Valentine’s Day Science Activities that kids will love.

The simplest science experiments are often the most fun, the ones you keep coming back to time after time. Especially if you have preschoolers looking for a messy busy activity. One of our most popular go-to activities is simply vinegar and baking a base. Even my 4th grader still enjoys these activities.

There are so many variations on what you can do with it, add a little food coloring, a few props and science items and you can create an experiment that lends itself well to any theme. Like this, Fizzy Heart Science Experiment – what a fun way to include a little Valentine’s fun in their day today. 

Fizzy Heart Science Experiment

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Fizzy Heart Science Experiment

Anytime I tell the kids that they get to have their hands get a tad bit messy, they’re on board 100% for any type of learning activity fun. And while this fizzy STEM activity is fun, they love that it’s a Valentine’s Day-themed activity as well.

>> See more Valentine’s Day Activities for Kids

I’ve found that over the course of my teaching the kids at home, they really respond well to themed activities and themed learning packets. It just helps them find a tad bit more excitement in gearing up for learning for the day.

Using this science activity is such great motivation! The kids will love being a part of this exciting experiment that they can help create and watch fizz! This is such a great hands on activity for all ages to be able to see science and STEM learning in action.

When you can give them the tools that they need to create experiments on their own, there isn’t really anything better than that! Besides being there with them to create and have fun!

Don’t forget to check out other Fizzy Experiments Your Kids Will Love.

Recommended Valentine’s Day Books

Don’t forget to pair up all your learning activities with some great books as well. Since this STEM activity for kids is heart-themed, it just makes sense to have some Valentine’s Day reading also.

Themed book reading is always a great exercise to add to the year. This is a simple and easy way to get the kids to want to read more without having to make it seem like a “lesson” or a “chore”. My kids love to have books that match well with the time of the year. This helps them get extra excited about holidays and gives them something fun to look forward to as well.

My trick and tip are to have books placed all over the house. This is the easiest way for them to grab a book and sit down and read, no matter where they are. They can literally be in any room of the house and have a book, right there waiting.

Below you’ll find some of our favorite reads for this time of the year but feel free to add in your own as well. It’s also a good idea to not put all the books out at once and have some to rotate as well. This will keep the books fresher longer and give them something to look forward to.

Day It Rained HeartsDay It Rained HeartsThe Biggest Valentine EverThe Biggest Valentine EverTurkey's Valentine Surprise (Turkey Trouble Book 6)Turkey’s Valentine Surprise (Turkey Trouble Book 6)There Was an Old Lady Who Swallowed a Rose!There Was an Old Lady Who Swallowed a Rose!A Crankenstein ValentineA Crankenstein ValentineLove, EscargotLove, Escargot


Fizzy Heart Science Experiment Supplies

Gather up the list of simple supplies to get started on this fun activity! Most of these supplies you already have at home.

Wilton Nesting Heart Cutter SetWilton Nesting Heart Cutter Set5ml Liquid Droppers Medicine Silicone and Plastic Pipettes Eye Dropper with Bulb Tip for Kids Candy Molds (8 Pack)5ml Liquid Droppers Medicine Silicone and Plastic Pipettes Eye Dropper with Bulb Tip for Kids Candy Molds (8 Pack)McCormick Red Food Color, 1 fl ozMcCormick Red Food Color, 1 fl oz


Fizzy Heart Science Experiment supplies

Fizzy Heart Science Experiment Instructions

First, determine how many hearts you want to make. This experiment is pretty fun and the kids will beg for more so mix up a good-sized batch!

In a large bowl place your baking soda and slowly add water, mixing with a spoon first and then your hands to get it well mixed. You want it just a bit wet but still firm, like a gritty toothpaste.

fizzy stem experiment

To make it themed for Valentine’s Day add some red food coloring and glitter for good measure.

If you are using cookie cutters place them on a baking sheet or another pan.

Press your mixture firmly into each cookie cutter to fill. This is a great job for the kids! They’ll be more than happy to get messy and push the mixture down night and tight! This is the perfect job for them!

Valentine's Day heart experiment

Place in the freezer for a couple of hours.

Remove the hearts from the freezer.

Provide your child with a bowl or cup of vinegar and droppers or syringes to use on their frozen baking soda heart.

fizzy heart stem experiment

The fun is in watching how the two react together to change texture and shape.

fizzy stem experiment

As they slowly add vinegar this experiment will last a little while but I promise you they will beg for more so I will have a couple of hearts on hand!

They’re going to love the fizzy outcome and you’re probably going to be making this activity over and over again!

Have them talk about what they think will happen with more drops or fewer drops added. This is such a great way to work on hypothesis learning and theories, too!

fizzy stem experiment

Fizzy Heart Science Experiment

You'll love this fizzy experiment that will make your Valentine's Day super special so grab your supplies and get started!


  • Baking soda
  • Water
  • Silicone molds or cookie cutters
  • Vinegar
  • Bulb droppers/medicine dispensers
  • Food coloring
  • Glitter


    1. In a large bowl, place your baking soda and slowly add water, mixing with a spoon first and then your hands to get it well mixed.
    2. Add some red food coloring and glitter.
    3. Place your cookie cutters on a baking sheet or another pan.
    4. Press your mixture firmly into each cookie cutter to fill.
    5. Place in the freezer for a couple of hours.
    6. Remove the hearts from the freezer.
    7. Provide your child with a bowl or cup of vinegar and droppers or syringes.
    8. Let them slowly add vinegar to the frozen baking soda heart.
    9. Kids will love watching how the two react together to change in texture and shape.

Recommended Products

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Pretty cool, huh? I know you love to make some more experiments like this so browse all of my other posts too! Enjoy!

More Valentine’s Day Activities

Make sure to check out these other great Valentine’s Day activities! When the kids are geared for learning, you can never have too many fun-themed activities for them to do! The following activities are ones that they’re going to love doing as well! Plan a whole day of fun learning activities for the kids to do and make sure to include the ones listed below.

Simple Heart Experiments

Looking for a way to incorporate science and Valentine’s Day? Here is a list of simple heart experiments that are Valentine’s Day-themed!

Valentine STEM Activities

If your kids love STEM activities, you must try these Valentine STEM Activities packed with exciting science experiments, slime recipes, engineering a structure challenge, and more!

Valentine STEM Activities for Kindergarten

Valentine’s Day Treasure Dig

Valentine’s Day Letter Puzzles

Valentine’s Day Lava Lamp Science Experiment by STEAMsational


  1. Shari Barry says:

    Oh my goodness this looks like a blast. I definitely want to try this with my Kindergarten class. Thank you.

    1. Wonderful! Let me know how it goes.

  2. My students this year Love Live vinegar and baking soda reactions. Thanks for sharing this Valentine’s Day activity!

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