Acidic Milk Lab

Measuring pH changes when acid is introduced in cheese making.

Key Terms:

independent variable: A variable is any factor, trait, or condition that can exist in differing amounts or types.  The independent variable is the one that is changed by the scientist.

acid: Any chemical compound that will raise the amount of hydrogen ions (H+) above the amount of hydrogen ions found in water

base: a solution that has an excess of OH- ions above the amount of hydroxide ions found in water.  Another word for base is alkali.

Hydrogen ion: A hydrogen atom that has no electrons, and therefore has a positive charge.  It is highly reactive.

pH: A scale that measures how acidic or basic a solution is. The scale measures from 0 to 14, with water a neutral substance with a pH of 7.


Instead of predicting an exact value, for this experiment we will be predicting a relationship. In other words, what is going to be the trend of the data that we are about to collect?

For this experiment, what do you think will happen to the amount of cheese as we increase the amount of acid used? Will it increase or decrease? Make a hypothesis stating whether you think the amount of cheese will increase or decrease as we use more acid to make our cheese. Make sure your hypothesis includes an explanation of why you think this will occur.

Hypothesis (may look like this)

I think the amount of cheese will __________________________ (increase or decrease) as we use more acid to make our cheese, because_______________________________________________________________.


Acid Used    /   Amount of Cheese Created