If the alkali or acid used for CIP cleaning enters the fermentation broth, it is a serious "quality accident" and should be dealt with according to the actual situation.

why are the PID based systems seemingly more popular than a PLC? (for the DIY crowd) is it that PID's are somewhat plug and play, while a PLC requires knowledge of how to create a program? he deems that a PLC would be a cheaper and more customizable option