Kraft processed cheese singles, at least the full fat version, will not be the same anymore. You won’t notice any change in taste though because the only difference will be a substitution of one preservative for another. Sorbic acid is out, natamycin is in. Why? Not because it is a more effective preservative. Both inhibit the growth of moulds, yeast and fungi. But since it is isolated from a soil bacterium, natamycin can be promoted as a “natural” preservative. And that sells! The curious thing is that sorbic acid also occurs in nature having been first isolated from the berries of the rowan tree. It is a relatively simple molecule and can be easily synthesized. Although the synthetic version is identical to the compound found in nature, legally it has to be termed “artificial” because it is not extracted from a natural source. The substitution of natamycin for sorbic acid is a marketing, not a scientific move. Its sole purpose is to cater to the common but mistaken belief that natural substances are somehow safer than synthetic ones. This romanticized view ignores the legions of natural substances like botulin, ricin, aflatoxins, fumonisin, brevetoxin, tetrodotoxin and domoic acid that put synthetics to shame when it comes to toxicity. But what is wrong about catering to popular desires even if these are not backed by science? What harm is there? In this case there is no harm because natamycin is an effective preservative, but the replacement of sorbic acid was not straight forward. Kraft worked on this “problem” for five years, obviously at considerable expense. And that expense is sure to be passed on to the public. Consumers will pay for work that was totally unnecessary. Misguided beliefs have more than one type of cost.