A number of improvers which can be used successfully in fast breadmaking processes have a large rheological effect in tests at the normal dough-testing temperature of 30". The exception is potassium bromate which has only a small effect. By raising the dough temperature to 40" or 50", corresponding to the temperatures reached towards the end of proving and during the early stages of baking, the slow bromate improvement is accelerated and a delayed but large rheological effect can be demonstrated. This delayed high-temperature effect can account for the successful use of potassium bromate as an improver, either alone or with other compounds, in rapid breadmaking processes. The dough-softening effects of a bakers' compound fat and of urea were no greater at 50" than at 25".