A machine for separating serosa from mucosa is disclosed. The machine comprises two peeling rollers (15,16), or one peeling roller or belt (26) and a stationary member (25). The stationary member can comprise a blade. The separation between the two peeling rollers, or the one peeling roller or belt and stationary member is about equal to or less than the thickness of a harvested intestine ribbon. The separation has a proximal and a distal end. The machine also comprises first means for rotating the one or more peeling rollers or the peeling belt at a first speed. A pull roller (18) is adjacent to the distal end of the separation. The machine further comprises second means for rotating the pull roller at a second speed. The second speed is less than the first speed of the first means for rotating. The source of the nonseparated serosa-mucosa layer can be a harvested intestine ribbon of a mammal. Separated serosa is useful in the manufacture of catgut sutures.