The actor spoke to Jobs' friends and colleagues and read up on the guy to perfect his portrayal and even adopted the great man's fruitarian diet and gait.
He tells Wenn, "I wanted to honour this guy and I couldn't afford to not resemble him because he's so well documented.
"I started by reading books and watching video and listening to people tell tales and stories. I started consuming the things he consumed. I started studying the entrepreneurs he admired and listening to the music he listened to and eating the food he ate and walking the way he walked.
"He would go for a walk when he wanted to have a meeting with someone and I just started doing that and walking without shoes on and wearing (sandals) Birkenstocks and going for one hour walks every day and trying to walk like he walked. Making those kind of changes to your body is a shock.
"When you're not used to eating a certain way it changes your body when you change your diet. Your body rejects walking the way Steve Jobs walks because you're physiologically built to walk the way you walk and every person on this planet has a unique gait that we can actually measure and quantify: you could use it as a security code if you wanted. Your body has to rebuild to walk that way so it was uncomfortable and served its purpose."
Director Joshua Michael Stern insists the research Kutcher did really worked: "When I took my first meeting with Ashton I already felt he was channelling Steve. On our second or third meeting he did want to take them while walking. We would take these long walks and talk about the character. I realised he was just living the character."