Interview with Llewellyn Smith, E. D. Smith - Kettle Cooking was Replaced by Continuous Cooking
Essentially we used to have, in the olden days, lots, and lots of kettles where you are cooking various things. Well those kettles disappeared over time, although there are some still there today. And the majority of the production moved to this closed system of continuous cooking rather than batch cooking. So this allowed for less product loss due to evaporation. It allowed for better flavour profiles because you didn't have to heat the product as high for as long a temperature to get to a proper sterilization. And it allowed you obviously to increase your efficiency, less handling, less opportunities for mistakes, and eventually we actually ended up having computerized closed continuous cooking systems.