Part of the Ice and Dilution school. Class 5 of 6.
The capability: you can move a drink's dilution from the shaker to the container and get it right.
Prerequisites: Module 43.
The practice
Make the drink correctly by hand. Measure the finished volume against the sum of the ingredients. That difference is the dilution fraction, per Module 43.
Batch it at that fraction.
Taste the batch straight from the container at service temperature. It should taste correct there — that is the verification and it is the whole test.
Then pour one over ice and shake another with ice. Taste both. Once, and nobody shakes a batch again.
And label the container — contents, date, and dilution status.
The reference
The hand-built version, tasted alongside the batched one.
What you are building
The arithmetic and the labeling habit together, because the failures in batching are almost entirely preventable and almost entirely not prevented.
Double dilution is not carelessness — shaking a margarita is muscle memory and a container does not visually announce that the water is already in it.
Verification and boundary
The container taste, at service temperature, before every service.
Boundary: batch labeling, dating, shelf life, and cold holding are governed by the local health authority.