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TOPIC:

Why is mayonnaise white and smooth and creamy?

HowIngredients List

2 Jumbo Egg Yolks (separate and discard the whites)
3 Teaspoons bottled Lemon Juice
1 ½ cups vegetable oil
1 Teaspoon Onion Powder
½ Teaspoon Salt
½ Teaspoon Sugar

Pinch of paprika (optional)

 Supplies List

  • Electric Mixer with Whip attachment  OR   Hand Whip or Whisk
  • 1 ½ to 2 quart mixing bowl you can hold easily
  • Liquid measuring cup
  • Small bowl, like a cereal bowl

 
Instructions

  1. make sure your space is as clean and uncluttered as possible.
  2. assemble the list of supplies and ingredients
  3. wash your hands
  4. separate the eggs by using an egg separator or
    1. by breaking one egg and gently pouring the egg into your hand
    2. allow the egg white to flow through your fingers (repeat for the next egg)
    3. wash your hands
  5. place the egg yolks into a separate bowl
  6. carefully measure the lemon juice into the mixing bowl
  7. carefully measure the oil into the liquid measuring cup
  8. add the egg yolks to the lemon juice and whip until frothy.  It is important to whip all of the mixture at the same time.  You can do this by hand with a whisk, but it takes a lot of effort. 
  9. allow the mixture to rest about 5 minutes (and if you have been whipping by hand you need a break too).  This will help the acid level of the lemon juice to kill off any stray germs in the egg yolks
  10. now we are ready  for the oil. As you whip, pour the oil in a very, very thin stream into the eggs and lemon juice. It should take about 2 ½ minutes to incorporate all of the oil.   It is extremely important to add the oil at a steady rate.  If you are doing this by hand have some one help you with the oil so that you can keep whipping.
  11. add in the remaining ingredients.  Your mayonnaise should be thick and creamy looking. It should be able to stand up on its own.  You should be able to turn the bowl on its side without the mayonnaise running out.  If it to runny, brainstorm why? Try it again if you want.

If I told you before you started making mayonnaise that it was mostly oil would you have believed me?  It looks nothing like oil. There is a good reason for that!  The word is EMULSIFY.  Emulsify literally means that 2 or more insoluble liquids are suspended together, in this case the oil and lemon juice. The lemon juice and the oil do not mix together to form a new molecule, instead every molecule of oil is surrounded by a microscopic amount of lemon juice. This is kind of like two friends holding hands.  They don’t become a new person just because they are holding hands, but together they are different than when they are separated.  The friends are emulsified.

 Now for the chemistry part.  So the lemon juice coats each molecule of oil keeping the oil molecules from reforming their liquid state.  Thus, it is important to remember that mayonnaise is not a small amount of lemon juice blended into oil, but is instead, a large amount of oil blended into a tiny amount of lemon juice.  To get the lemon juice around the oil you must put the oil into the lemon juice the give it the chance to coat each molecule.

Lets think back to the discussion of the friends holding hands.  What would stop one of those friends from letting go of the other friend’s hand? If he did let go he would break the emulsified state.  With mayonnaise we don’t want the emulsified state to break so we add a stabilizer.  This is like gluing the friends hands together.

The stabilizer is the molecule lecithin, found in egg yolks.  The lecithin in the egg yolk acts like glue holding both the oil and the lemon juice components in an emulsified state. No matter how much you mix the oil and lemon juice together, it will always separate (break) into a gooey mess unless you include the egg yolk as a stabilizer. This is what keeps mayonnaise fluffy.

So what does the rest of the stuff like the salt and sugar do? That has to do with a different type of chemistry.  We will leave that for another time and simply say the rest of the ingredients help the mayonnaise taste great!


TryNow comes the good part.  You get to try it out.  Don’t be nervous or concerned.  The worst thing that happens is a few eggs and oil end up in the trash instead of the table.  Be confident and know that in trying you have succeeded even if the experiment does not.

No matter what happens, take some notes, get a few pictures and preserve your efforts.  The only mistake made is one not learned from!

 

What was your result?

  • You have produced some lovely mayonnaise.  Way to go Hot Shot!
  •  It was mayonnaise and then slid into a goop.  Great try!
  •  Nothing happened.  Try again going slower this time!
  •   It ended up all over the wall, the floor, the ceiling . . .    Oops! Better get cleaning! 

 

Emulsify – what other things can of think of that are emulsified?  Make a list and include it with your report!