How to Determine Which Products Contain Acids or Bases
- 1). Tear of a piece of the pH paper.
- 2). Dip the paper strip into the product sample, take it out after two to three seconds.
- 3). Compare the paper color with the scale that comes with the pH paper. Typically, if the color is red or orange then the product contains an acid. If the color is blue or dark blue, the product is a base.
Source...