Reader DEA wrote in to say that he figured out the Caramilk secret a long time ago.
The short story is that I have been involved with magnetic resonance imaging (MRI) for many years now and near the beginning, in the late 80’s, we imaged anything and everything of interest. Of course, Caramilk chocolates were among the first samples of interest. I have included one such image with this email as an attachment (annotated).
Short story again is that one can identify two different shadings of the chocolate coating (I can do image enhancement etc, but it is there and I have tried to annotate the gif to highlight the regions I am talking about — I have better images somewhere but they are hard to find after 20 years; this work was never published). Anyway, there are distinct, sharp edges that separate the ‘top’ from the ‘bottom’ of the coating (highlighted in the image), indicating that the bottom has been in a mold at a different temperature (thermal history) than the top. MRI experiments of this type can be made sensitive to subtle differences in the thermal history of the chocolate and the effect is now well known. So we have evidence for a simple process of filling the bottom layer and then pouring a top layer to create the product.
But how does one get the gooey center into the mold and then get such a nice top layer onto it without creating a liquid mess? First, the center component must be hard to retain its structural integrity during the process. This is probably the real secret…the center part is indeed hard when the product is made, but softens afterwards due to an (added) enzyme that causes a reaction that occurs afterwards. I am not and never have been an employee of the company that makes this product but I am fairly sure that what I have described comprises the ‘secret’… We considered publishing this all those years ago but decided that some things are best left to the imagination (like Santa Claus and the Easter Bunny etc)…
Or Mann’s methodology.