Pulling strings
In the bakery language, stringing or stringy bread is a " bread disease " (bread defect, defective quality of bread), which is caused by the microbiological decomposition of the bread crumb . Various Bacillus strains, such as Bacillus subtilis , are responsible for this.
Causes and Epidemiology
In the last few years the old, almost forgotten bread disease of stringing has become more common again. It occurs mainly in the summer months due to "hay or potato bacteria". The reason for the significant increase is the change in cultivation habits. Fewer pesticides and insecticides are used, which means that grain and flour are highly contaminated by these bacteria. Long threads of mucus form in the bread, which gave the bread disease its name. At first you can notice a fermenty, fruity smell, after which the crumb is damaged to the point that it becomes sticky. When the bread is broken open, threads and discoloration of the crumb are clearly visible in later stages.
Effect of sourdough
Only unleavened or weakly leavened light-colored breads are affected, as they become inedible. Although the bacteria largely die off during the baking process, the spores are heat-resistant and germinate when they cool down to 30 to 40 ° C, their optimum temperature. Sourdough (acid) kills the bacteria and suppresses the germination of heat-resistant germs. The reason for this is the combined effect of the acidic pH of lactic and acetic acid . But other antimicrobial substances in sourdough also reduce or prevent this bread disease.
Individual evidence
- ^ J. M. Thompson, W. M. Waites, C. E. R. Dodd: Detection of rope spoilage in bread caused by Bacillus species. In: Journal of Applied Microbiology. 85, 1998, pp. 481-486, doi : 10.1046 / j.1365-2672.1998.853512.x .
- ↑ Gottfried Spicher, Markus J. Brandt (Ed.): Handbuch Sauerteig. 6th edition. Behr, Hamburg 2006, ISBN 3899471660 .