calandria and whirlpool function
Andrew,
Quite a problem, indeed. A full rolling boil is necessary to allow the Dimethyl sulphide that has converted from S-Methyl methionine to oxidize to Dimethyl sulphoxide or to volatize and leave the kettle through the stack. Hough, Briggs, Stevens, and Young have a beautiful illustration of this reaction on page106. Lewis and Young believe that a full rolling boil stabilizes beer in three senses: it sterilizes the wort rendering it bacteriologically stable; it inactivates any enzymes that survive mashing; and it precipitates a protein-carbohydrate-polyphenol complex called hotbreak.
I don’t believe that retrofitting an internal calandria is the best answer to your abstruse problem. Given that you have a kettle/whirlpool it seems that an external calandria might provide a better alternative. Kunze believes that an external calandria provides a slight overpressure in which the wort can be heated to 215-223 degrees Fahrenheit. This results in improved bitterness yield from hops, coagulable proteins are completely precipitated, and a controlled circulation occurs. In addition, the improved boiling also produces a lower pH, a lighter color, a cleaner taste and improved flavor stability. Assuming that your brew house is steam fired an external calandria with a tube and shell heat exchanger as illustrated in Sing and Heldman might provide the most efficient means to the end of your problem.
Enkidu
P.S. Congratulations for your medal at the world beer cup and tell Kari that I said hello.
Drink the beer, destiny of the land.