Candy Heart Experiments You Need to Try this Valentine’s Day

The kids are going to have such fun learning with these Valentine’s Day candy heart experiments.

Candy heart experiments for Valentine's Day

I have something to admit.

I do not like conversation hearts! What do you think of them?

Those little hearts just don’t do it for me, despite my sweet tooth. Which is why it’s not unusual for me to have a half-empty bag of them leftover from the year before.

Nothing goes unused in a preschool classroom, so I love using conversation hearts in early learning activities. One of my favorite things to do with those stale candies are simple candy heart experiments.

Valentine’s Day science with candy heart experiments

I’ve done these candy heart experiments with a variety of preschool classes, and the kids always love them.

We start with one basic question. What do you think will happen to the conversation hearts if we put them in different liquids?

Labeled jars for candy heart experiments

Materials you’ll need for this Valentine’s Day science experiment

To get things started, find some kind of container. Depending on the year, we’ve used empty bottles from our recycling stash, or glass mason jars. Grab what works best for you.

Next up is deciding on which liquids to use. Since these experiments are meant to be easy, I usually use liquids we have on-hand.

Some liquids you might want to use (but this list isn’t exhaustive):

Water
Vinegar
Soda
Rubbing alcohol
Corn syrup
Hand sanitizer
Juice
Soap

Help the children make predictions about what will happen

After settling on what liquids to use, it’s time to make some predictions.

I explain what a hypothesis is, and then ask the children to think about what might happen. Take a little bit of time to record what the children have to say – on construction paper, on a white board, on chart paper, etc.

There’s a free printable recording sheet that you can download at the bottom of this post.

Candy heart experiment predictions

It is always wonderful to listen as the kids discuss what they think will happen. Sometimes, the predictions aren’t on topic, but most of the time it’s obvious the kiddos are really thinking about the possibilities.

I think my favorite prediction ever was, “The hearts will explode!” Although, “Maybe the hearts will sparkle!” is right up there at the top, too.

Recording observations during candy heart experiments

How to set up easy candy heart experiments in preschool and kindergarten

Once the predictions are recorded, it’s time to get the experiment underway.

Put liquids into the containers you’re planning to use. Be sure to leave one empty for your “control”. I explain to the kids that our control container is so we remember what the candy hearts normally look like.

By this point, the kids are usually clamoring to add the conversation hearts to the containers of liquids.

We usually add about 10 hearts to each container, taking a moment to watch for any reactions.

Observing candy heart experiments

Once all of the containers are filled, make some initial observations.

Be sure to record what the kids notice.

Set a timer for an hour or two, and then head back over and see if anything’s changed. I like taking pictures of the hearts along the way, and the children love helping with that part too.

Candy hearts dissolving in soda during candy heart experiments

From there, it’s up to you how long to let the candy heart experiment go on. We tend to let things go for a couple of days, observing and recording what we see.

Sometimes the kids like to “help” things along after a couple of days. And by help I mean, stir everything up. Yes, this means we end up with some goop in the containers, but it adds another layer to the experiment.

The final results of our candy heart experiments

Some of the observations kids have made over the years:

“Look! Tiny bubbles are coming up from the hearts!” {Right away in the vinegar}
“Hey, some of the hearts are floating now!” {After an hour or so in the water}
“What’s all that extra stuff floating around in there?” {Commenting on the extra sediment that seemed suspended in the rubbing alcohol towards the end of the day}
“They melted the fastest!” {The hearts we put in the soda}
“These didn’t really do anything. But it sounds fun when I shake it!” {The container with just air and hearts}
“What is wrong with these hearts? They aren’t melting at all!” {The hearts in the corn syrup}

Ideas for extending the candy heart experiments

There are so many ways to change or extend this experiment. Change how many hearts are in the containers and see if the results are different. Incorporate even more liquids. Try different types of candy hearts. Etc.

You can even set the kids up with their own science journals for this experiment. This way, each child can draw and/or write their predictions and observations along the way.

I’ve even got a handy-dandy free printable that’s available to my email community to create a science journal for the kids. It can also be used as a simple recording sheet, too.

Have you tried out any candy heart experiments for Valentine’s Day? If so, what did you do and what were your results? I’d love to hear all about it in the comments below.

Preschool Lesson Plans for Valentine’s Day

Save time and get right to the playful learning with our printable lesson plan sets. Each set includes book suggestions, printable plans, over 30 learning activities (both whole group and centers) related to the theme, and corresponding printables.