Hearth bread was made from 12 blends of four flours, which varied in protein content (10.2-14.3%) and protein quality, by a straight dough baking procedure. Doughs were mixed using a Farinograph operated at 63 rpm for variable mixing times (5-25 min), and proof times were also varied (35-60 min). Loaf volume was strongly positively related to protein content (r=0.95), Farinograph dough development time (FDT) (r=0.88) and Farinograph dough stability (FDS) (r= -0.97), but not to Zeleny sedimentation volume, SDS sedimentation volume or Mixograph peak time (MPT). Similar observations were found for the form ratio of loaves. The positive relationships between protein content on the one hand and loaf volume and form ratio on the other were only observed at medium (15 min) and long (25 min) mixing times, but not after a short mixing time (5 min). Furthermore, loaf characteristics were strongly affected by the process parameters, giving independent effects on loaf volume vs. form ratio. (C) 1999 Academic Press.