Spore-forming bacteria (Bacillus mesentericus and B. subtilis) occurring on wheat and hence in flour. The spores can survive baking and then are present in the bread. Under the right conditions of warmth and moisture the spores germinate and the bacteria convert the bread into sticky, yellowish patches which can be pulled out into rope-like threads, hence the term ‘ropy’ bread. The bacterial growth is inhibited by acids. Can also occur in milk, called long milk in Scandinavia.
Subjects: Medicine and Health.