There's science in serving drinks (6)
I believe the answer is:
optics
'science in serving drinks' is the definition.
'optics' can be an answer for 'science' (optics is a kind of science). I am unsure of the 'in serving drinks' bit.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for optics that I've seen before include "Science of vision/light" , "Scientific studies of light and vision, the eyes" , "Science concerned with vision" , "Science of light/vision" , "Devices to measure out alcohol" .)