Jigger Calibration and Pour Accuracy

The capability: you know what your jiggers actually hold and what your pour actually delivers, and so does everyone else on the bar.

Prerequisites: Modules 3, 5.

The practice

Fill every jigger in the building with water into a graduated cylinder. Two minutes, and it frequently finds a mismatch nobody suspected, per Module 3.

Then watch three people read a jigger. To the rim, to a line, to a meniscus are three different volumes and nobody has been shown which one the house means.

Then the free-pour test. Five pours per person into a graduated cylinder, framed as calibration because that is what it is, per Module 5.

Record the spread within each person and between people.

Then re-pour weekly for a month and watch the spread narrow.

The reference

The graduated cylinder. This is one of the few classes with a genuinely objective reference and that is worth using — a pour is right or it is not, and the cylinder settles it.

What you are building

Calibration, which is a motor skill and which decays.

And the knowledge that it decays — free-pour accuracy degrades with speed, with fatigue, and with never having been checked, which is why the re-pour matters more than the first test.

Verification and boundary

The spread, recorded. Within each person and between people.

Boundary: alcohol content and service obligations are governed by the Texas Alcoholic Beverage Commission.