What Makes Peanut Butter Stay Smooth? 1st grade Science Project

Peanut butter is made with peanuts. If you ever tasted a peanut you know that it is crunchy. Once the peanut is turned into peanut butter it is smooth and creamy.

When you open a jar of natural peanut butter, you will notice it has oil on top. Once you mix the natural peanut butter it becomes smooth and creamy. This doesn’t happen with commercial peanut butter brands from the store such as Skippy or Jiffy. When you open a regular jar of peanut butter, it will look smooth and creamy without mixing it, why?

What makes peanut butter stay smooth?

This is a good question. It is because regular peanut butter goes through a process called hydrogenation.

You may have heard of the term hydrogenated oils. Sometimes there is hydrogenated oils in the food we eat. These are oils that have additives in them to turn them into a solid.

Learn more below

Find out how peanut butter stays smooth through the process of hydrogenation with this science experiment below.

This experiment is quick and easy and perfect for kindergarten, 1st grade and 2nd grade students.

Scientific Method

In this experiment you will follow the scientific method

  • Ask a question
  • Formulate a hypothesis (make an education guess on what you think will happen)
  • Conduct the experiment
  • Collect data
  • Make a conclusion


Why does natural peanut butter get oily and commercial peanut butter stay smooth and creamy?


Why do you think natural peanut butter is oily? Why do you think commercial peanut butter is smooth and creamy?


Mix different types of peanut butter to find out which one stays smooth and creamy


  • 1 jar of natural peanut butter
  • 1 jar of Skippy creamy peanut butter
  • 1 jar of Jiff creamy peanut butter
  • 1 spoon
  • 3 cereal bowls


Step 1

In the first bowl add two large spoonful’s of the natural peanut butter.  Mix it well with the spoon.

Step 2:

In the second bowl add two large spoonful’s of the Skippy creamy peanut butter.  Mix it well with the spoon.

Step 3:

In the third bowl add two large spoonful’s of Jiffy creamy peanut butter. Mix well with the spoon.

Step 4

Let both bowls of peanut butter sit still for 1 hour.

Step 5:

Look what happened and record your results.

What Happened to the Bowls of Peanut Butter? Conclusion

The Skippy and Jiffy creamy peanut butters will still look creamy and smooth.  The natural peanut butter has a layer of oil on top.


Peanuts contain oil naturally.  When peanuts are mashed together to make peanut butter, the oil separates from the peanut.

When you mixed the natural peanut butter the oil mixed with the peanuts.  When you let it sit for an hour the oil separated itself from the peanuts again.

 This caused the oil to sit on top of the peanut butter.  Why doesn’t this happen to the Skippy or Jiffy peanut butter?

 Because it was put through a process called hydrogenation.  

Hydrogenation is a chemical reaction that turns liquid oil into solid fat by combining the oil with hydrogen gas.  The hydrogenation process changes the atoms in the liquid oil into a solid fat this makes the peanut butter smooth and creamy.

In other words hydrogenation turned the liquid oil into a solid fat. The solid fat does not separate.

hydrogenated oils have a lot of trans fat and aren’t good for your heart.

Nature peanut butter is better for you than regular commercial peanut butter because it does not contain hydrogenated oils.

A closer look

Look at different labels on foods.  See how many ingredients contain hydrogenated oils. You’ll be surprised.