The 47-year-old star is thrilled to have developed a close Friendship with the rocker - who reprises his role as Captain Jack Sparrow's father in 'Pirates Of The Caribbean: At World's End' - and loved hanging out with him on the set of the new swashbuckling adventure - despite being unsure about his friend's tipple of choice.
Johnny said: "He's a fascinating man, you know. I've known him for a long time. To get periods on set where it's just him and me hanging out, sitting around and yakking about music, movies whatever, was a real pleasure.
"I'm a wine man and I do like a good glass of red. So I would have my glass of wine and Keith would have his usual.
"I've no idea what it is, because it looks like nuclear waste and it's a combination only he would know."
Johnny - who has children Lily Rose, 11, and nine-year-old Jack with partner Vanessa Paradis - says his son still loves to see him as his 'Pirates of the Caribbean' character Jack Sparrow - until his friend, 'Iron Man' star Robert Downey Jr., comes over.
He added in an interview with Radio Times magazine: "Oh yeah, he's still into Captain Jack. But at the same tie he sees me every day, so he's super used to Papa.
"And you know, Bob Downey, who is an old friend, comes over to the house for dinner and Jack's like, 'Oh my God!' So then Captain Jack becomes secondary to Iron Man."