Cloudy Bacteria

Almost all our food has preservatives added.  This is to stop food from going bad.  But do preservatives really stop the growth of bacteria?

You will need:  salt, white vinegar, clear drinking glasses, chicken bouillon cube, measuring cup, measuring spoon, masking tape, marker.

  1. Dissolve 1 chicken bouillon cube in 1 cup of hot tap water.
  2. Pour the mix into 3 glasses. Each glass must have the same amount.
  3. Add 1 teaspoon of salt to a glass. Use  the masking tape to label the glass “salt.”
  4. Add 1 teaspoon of vinegar to the 2nd glass. Label it “vinegar.”
  5. Label the 3rd glass “control”, because it won’t have a preservative.
  6. Place the 3 glasses in a warm place.  Leave them for 2 days.  Discover which glass is cloudier.

What Happens:  The glass with the vinegar is clearer than the others.  The “control” is the most cloudy. 

Why:

  • The cloudiness is made from large amounts of bacteria.
  • The other two glasses have preservatives: therefore, are clearer than the control.
  • This is because the preservatives slow  the growth of bacteria.
  • Vinegar stops the bacterial growth the best.
  • Food preservatives are important to help stop food from going bad.  They stop the growth of molds and bacteria.