Thermal processing is still the reliable work horse of food preservation, dating back to Napoleonic times when Nicolas Appert developed a method for preserving food in sealed glass jars. Later others developed metal cans for the same purpose, but it was almost another century before there was a scientific understanding of why heating and the exclusion of air worked as it did. In the meantime, canning was a haphazard technology with frequent failures.
Louis Pasteur observed that yeasts were respon…