Experiment 60

To determine the effect of heat upon cheddar cheese.

A. The melting point.

1. Place some grated cheddar cheese in a test tube. To determine the melting point place a thermometer in the test tube. Melt the cheese by immersing the test tube in water and heating the water. Compare the melting points of several samples of cheddar cheese. Notice the consistency of each cheese, its dryness, hardness, etc., before and after melting.

2. Repeat 1, but use the Kraft or other varieties of cheddar cheese that have been put in sealed or other types of containers.

B. Effect of temperatures above the melting point.

1. After observing the consistency and texture of the cheese from A1 and A2, put the tubes in warm water and heat to temperatures above the melting point. Notice all changes that occur.

C. Combining the cheese with milk.

1. Combine about 2 level tablespoons (14 grams) of grated cheese with 1/4 cup of milk (60 grams). Heat in the upper part of a double boiler. Note the melting point of the cheese. Continue heating and describe the changes that occur in the cheese-like mixture.

Does the dryness, texture, or fat content have any effect upon the melting point? From the results obtained, what would you conclude about combining cheese with other foods? Should cheese be heated directly over or under the fire? If so heated, what temperature should be used? Should cheese be covered with sauce and bread crumbs in macaroni and cheese before putting in the oven? Why?

Sample of cheese

Melting point

Texture of cheese before melting

Effect of melting and heat