Preservatives in bread are seen by bakers as key in delaying spoilage. But while consumers, the media and retailers generally regard convenience as a good thing, they share a negative perception of preservatives.
Yet preservatives achieve the keeping quality we all demand. There have been many attempts to find ’natural’ alternatives to the calcium propionate (CP) widely used, including the use of vinegar, natural ferments, modified atmosphere packaging, ’clean bakeries’ and... well, that’s the lot. These all have drawbacks, including cost, impact on flavour/texture or lack of effectiveness.
So why is there no alternative to CP? The simplest answer is that it’s still the best at reducing the rate of spoilage of stored bread. In some products, potassium sorbate has been used. It is better, weight for weight, at preventing mould growth than CP but, if added to dough, reduces yeast activity, so has to be sprayed on the surface of the bread after baking.
One other issue to consider is ’rope’ - bacterial spoilage that produces rope-like threads in bread and can cause food poisoning, forming rope-like strands in the crumb, and strong, un-breadlike odours. The anti-bacterial action of CP, both in the bread and our bakeries, has all but eliminated rope. But, if a replacement for CP cannot be found, the risk is that rope will reappear.