Warm milk
Warm milk was milk that had been heated above room temperature. Once heated, the milk's  amino acids acted as a mild sedative, helping one sleep. 

Warm milk was Reginald Barclay's drink of choice on the . () Captain Jean-Luc Picard's aunt  had a recipe for steamed hot milk toddy with nutmeg, which Picard shared with Doctor Crusher in 2368. ()

On two subsequent occasions, Crusher prescribed a  of warm milk toddy to Commander William T. Riker and Picard (with a dash of nutmeg) to help them sleep. ()

In 2373, Quark prepared warm Enyak's milk when Kira Nerys appeared "rumpled." () Similarly, Q suggested warm Kylerian goat milk to Captain Kathryn Janeway when she was having trouble sleeping. ()

Both Commander Chakotay and Neelix thought that warm milk was repulsive. ()

External link 
 

Beverages