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The Pectin Test: Science For Kids

Do your kids love jelly and science?

Jelly Unit: Pectin Test Learning Activity
What's really in a jelly jar?

What Goes Great With Jelly?


Certainly an ever-popular answer to that question is, of course, peanut butter, but spreading out beyond the goes great with jelly.


If you have young (or not so young, like me) ones at home, they are on a mission to find out how and why things work. While creating a homeschool jelly lesson plan, I thought it of upmost important to explain how jelly forms. Jelly is so readily available at the markets and stores, which is great, but the convenience also has us overlook just how much science goes into creating this delightful spread. I wanted my little scientists, to explore and begin to understand the reason that jelly is well, jelly-like, is because of some awesome science at play.

More Than Sugar

Jelly is sweet, absolutely, but there is more going on in that jelly jar than sugar. The key component in preparing delicious jelly, is a substance called pectin. Pectin is a starch that naturally develops in the cell walls of fruits and vegetables.

What makes pectin so important in jelly making, is its ability to thicken and hold the jelly together. Without the right pectin level, there's no jelly.

So peanut butter isn't jelly's best friend, it's pectin!

Now knowing jelly's special ingredient, it's time to test it! Grab your little scientist and let's get them working on the pectin test.


The Pectin Test

What You'll Need:

Various fruits:

strawberries, grapes, oranges

Rubbing Alcohol

Small jars with lids


Jelly Unit: Pectin Test Learning Activity
Pectin test completed along with the paired worksheet.

Let's Test It:

Step 1: Get your scientist hands on!

Have them prepare the fruit for testing by

washing, removing any stems, and stickers.

Jelly Unit: Pectin test learning activity
Scientists preparing the grape specimen.

Step 2: Boil each fruit type down in a small saucepan. Note: You will only need approximately a teaspoon of each fruit's juice for the test, so cook the fruit in small batches.

Step 3: Once the fruit has been boiled down, use a mesh strainer to strain each juice and remove any remaining skins or seeds. Pour the fruit juice into separate cups or bowls. Allow the juices to cool.

Step 4: Prepare the test jars. You will need an individual jar per fruit. In each jar, measure and pour in 1 Tablespoon of rubbing alcohol.

Jelly Unit: Pectin test learning activity
Extracting the various fruit juice specimens

Step 5: Add 1 Teaspoon of each of the cooled fruit juices to their individual jar.

Step 6: Close each container, and shake gently.

Step 7: Carefully observe the jars. Are there any noticeable changes?

Jelly Unit: Pectin test learning activity
Adding in the fruit sample

Step 8: Open each of the jars. Using a fork, comb through the liquid. Juices with the most pectin will form a jelly-like substance that a fork will not run through, while lower levels of pectin will only form small jelly-like particles in the jar.

Step 9: Record or discuss your findings.

Why is the pectin test helpful?

Knowing how much pectin is in the fruit juice is crucial to creating a proper jelly. Remember, without the right level of pectin, jelly will not form and hold itself together. Knowing if the pectin level from your fruit juice is too low, will tell you if you need to add a pectin supplement before

making the jelly, and potentially wasting your ingredients.

Jelly Unit: Pectin test learning activity
My little mad scientist shaking the juice


Let's Make This A Full Learning Adventure!

Visit Here For the Complete Jelly Lesson Plan.

Jelly Unit: Pectin test learning activity
There's a whole lot of fun and learning to be had with jelly!


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