Bacilli Spoilage in Part‐baked and Rebaked Brown Soda Bread

Brown soda bread had a pH of 7‐9 depending on the sodium bicarbonate concentration. Part‐baked bread developed ropiness after two days at room temperature. Bacillus subtilis, B. pumilus and B. licheniformis were isolated and their spores displayed D‐values in bread dough of 14, 10 and 56 min at 100°C. Germination and growth was examined in broth at pH 6‐10 and at 4°, 20°, 30° and 37°C. No growth was observed at 4°C and at pH 10. Rebaking of the part‐baked bread heat activated particularly B. licheniformis spores.