The processing and baking quality of bread wheat can be affected by both genetic and environmental factors and by interactions between them. Here we report on the genetic control of grain protein content, flour water absorption, dough and bread making quality in wheat grown in three experiments under differing environmental conditions. The research used a recombinant inbred line mapping population derived from a cross between two Australian cultivars, Drysdale and Gladius. Three field experiments were conducted, including one that was sown late in order to expose the lines to high temperatures during grain filling and one in a year in which conditions were unusually cool and wet. Genomic regions containing photoperiod sensitivity loci affected grain protein content while the Ha (puroindoline) locus on chromosome 5D was associated with loaf quality traits. Other QTLs (on chromosomes 2B, 3B and 5A) were novel and not associated with any known quality or phenology genes.