File this one under “not the smartest plan.”

A parolee tried to beat a urine test by concocting a phony sample made of orange juice and coffee, authorities said.

John Lee Walker, 32, of New Castle smuggled the crude concoction inside a small bottle of shampoo last month when he showed up at the state Board of Probation and Parole office in Center Township.

Not surprising, the plan quickly unraveled and Walker finds himself facing a new charge of attempting to use drug-free urine.

“It was a pretty desperate plan,” admitted Trooper Chad Savannah, the investigating officer.

The suspect’s latest brush with the law occurred Dec. 15 when he appeared at the parole office for a urine screening test, according to court documents.

The colder-than-body temperature of the sample was the first clue to its lack of authenticity, Savannah said.

Walker’s parole officer confronted Walker, who admitted trying to pass off the fake urine as his own. He removed the shampoo bottle from his pants and handed it over, documents said.

He “admitted to using heroin and cocaine and knew that his urine would test positive,” a police affidavit said.

He also admitted devising his ill-conceived homemade mixture.

“Walker related that he provided (the parole officer) fake urine which consisted of orange Kool-Aid and coffee,” the affidavit said.

Court records show that Walker’s extensive criminal record includes convictions in Cambria and Somerset counties between 2002 and 2011 for shoplifting, bad checks, corruption of minors, drunken driving and burglary.