activity

Oil and water don’t normally mix. But look at salad dressings: In many of them, oil and vinegar (which is made mostly of water) form a smooth, completely mixed combination—at least for a little while. What’s the secret? In this experiment, you’ll mix oil and vinegar on their own and then with some ingredients often found in salad dressings—will they help oil and water stay mixed?

safety
  • No safety considerations
difficulty
  • Beginner
time
  • 1¼ hours

hey curious cook—

Have you heard about our Young Chefs’ Club? Members get a themed (and kid-tested) box delivered each month!

Prepare Ingredients

1 cup plus 2 tablespoons
extra-virgin olive oil
6 tablespoons
red wine vinegar
1 teaspoon
Dijon mustard
1 teaspoon
mayonnaise

Gather Equipment

Masking tape
Marker
3
(6- to 8-ounce) clear jars with tight-fitting lids
Measuring spoons
1
 

Use masking tape and marker to label 1 jar as “Control,” second jar as “Mustard,” and third jar as “Mayonnaise.”

 
2
 
1 cup plus 2 tablespoons
extra-virgin olive oil
6 tablespoons
red wine vinegar

Add 6 tablespoons oil to each jar. Add 2 tablespoons vinegar to each jar. Screw lid tightly on jar labeled “Control.”

 
3
 
1 teaspoon
Dijon mustard

Add mustard to jar labeled “Mustard.” Screw lid tightly on jar.

 
4
 
1 teaspoon
mayonnaise

Add mayonnaise to jar labeled “Mayonnaise.” Screw lid tightly on jar.

 
5
 

Hold 1 jar in each hand. Vigorously shake jars for 30 seconds. Set aside jars. Repeat shaking with remaining jar.

If you’ve got a friend or sibling handy, one of you can shake two jars and the other can shake the remaining jar. Turn on some tunes and have a 30-second dance party!

 
6
 

Make a prediction: In which jar do you predict that the oil and vinegar will stay mixed the longest: the control jar, the mustard jar, or the mayonnaise jar? Why do you think so?

 
7
 

Observe your results: What do the jars look like right after you finish shaking them? Check on your jars every 15 minutes until 45 minutes have passed. What do you notice? Which jar kept the oil and vinegar mixed the longest? The shortest?

 
8
 

Eat your experiment: Turn your emulsions into a salad dressing. Add contents of 1 or more jars to large airtight container with lid. For each jar you use, add ¼ teaspoon salt and ⅛ teaspoon pepper to container. Place lid on container and shake to combine ingredients. Dressing can be refrigerated for up to 1 week. Shake well before using.