Carol Miles, head of the hard cider program at WSU in Mount Vernon, assesses the mouth feel of a hard cider.

Carol Miles, head of the hard cider program at WSU in Mount Vernon, assesses the mouth feel of a hard cider.


Washington State University is offering free online training for cider makers on how to test tannin levels in apple juice. Hard cider is one of the fastest growing segments of the alcoholic beverage market, and producers need to know how to ensure product quality and consistency, according to the university.
The online training module “How to Test Tannin Levels in Apple Juice Using Lowenthal Permanganate Titration” teaches cider producers how to analyze their raw materials so that their cider has a consistent mouth feel.

Tannin provides astringency, or a sensation of dryness in the mouth, but tannin levels in apple juice are inconsistent. Not only do they vary according to the apple variety, but tannin concentrations can vary in apples picked from the same trees in different years. Each batch of juice should be tested.

The training module includes segments on equipment and materials, setup, safety, and how to perform the laboratory procedure for the Lowenthal permanganate titration technique. The same technique could be used to test tannin levels in grape juice, tea, and other beverages.

Register here for the training, which will be hosted by Dr. Carol Miles, head of the hard cider program at WSU, Mount Vernon.