The metal legends' as-yet-untitled album is due for release in September, with final production finishing next week.
"The direction is embracing our past in the now," Hetfield told Rolling Stone. "We know what we know. It's hard to erase that. But to strip it down again, and get back to why we're doing this? Why did we write songs that way? The template was 'Master of Puppets' and the strength of that record. How can we do that now?"
The band hit the studio with 26 songs, reduced that to 14 with producer Rick Rubin before deciding on 11 to record. However, only 10 songs will make the final tracklisting.
"We feel this record is really good, especially after 'St. Anger'" said Hetfield. "It was very one-dimensional and abusive to the listener. That was the anger coming out. But this one is a lot more moody."
The album's tunes "are long songs ... we're talking seven-minute, eight-minute, nine-minute nutty-ass songs," Ulrich told Spin. "We don't make them long or short on purpose; you just kind of do what feels natural. We're not really gonna edit them."
"There's a lot of variation, a lot of fast, slow, melodic ... kind of hardcore, nutty super-fast speed stuff. It's a little more like how some of the earlier records were a little more dynamic within the songs."
Hetfield also revealed the album has a title, but refused to divulge it. Speculation hints at 'Mission Metallica,' the name of the website set up to update fans as to its proress.
"It's got a title and we're still playing with it to see if we like it. But I guess the album's done. It's still got to be mixed. All the singing, all the recording is pretty much done. And we're pleased with it."