# Triangle Testing: A Detailed Procedure for Blind Taste Tests of Beverages

From time to time we plan on performing a form of taste test, called a triangle test.  What follows is the basic framework that will be used in those future tests.

Background:

Performing a meaningful taste test is a surprisingly difficult task.  In the past we had often tried to express what it was we liked/disliked about the various options being tasted.  However after exposure to the book Blink, we realized this was perhaps an erroneous approach.  A much simpler approach is to perform a test with  the goal of determining if it is possible to tell the difference between two different beverages.

Equipment & Materials:

Equipment for performing a triangle test of two beverages.

Procedure:

Person 1:

1. Place one wine charm onto each glass.
2. Using the first graduated cylinder, pour equal amounts of beverages A into two glasses.
3. Record which glasses are beverage A on first piece of paper.
4. Using the second graduated cylinder, pour the same amount of beverage B into the other two glasses.
5. Recording which ones are beverage B, on first piece of paper.
6. Shuffle the order of the glasses.
7. Hide first piece of paper from person 2.

Person 2:

1. Record the original charms on second piece of paper.
2. Add a second wine charm to each glass.
3. Record the pairings of charms on each glass (optionally taking a photo as evidence).
4. Remove original charms.
5. Shuffle the order of the wine glasses.
6. Set aside one one glass.
7. Hide second piece of paper from person 1.

All tasters:

1. Drink some water to rinse your mouth before first taste.
2. Sample each of the glasses, being sure to rinse your mouth with water between samples.
3. Resample each glass as needed, rinsing your mouth between tastes.
4. Secretly record the charm of the glass you believe contains a different beverage than the other two glasses.

Once all tasters have recorded which glass they think contains the unique beverage, trace backwards through the charm mappings recorded on the pieces of paper, to determine which beverage is in each glass.

Worksheet:

Original Charm to beverage mapping:

 Glass Original Charm Beverage 1 A / B 2 A / B 3 A / B 4 A / B

Original charm to New charm mapping:

 Glass Old Charm New Charm 1 2 3 4

Observations by Tasters:

 Taster Charm on glass that is different A B C . . .