Pretty Stupid, Apparently.
In a June, 2014 article on the World Science Festival website entitled, The Mast Bros Unveil the Physics Behind Chocolate, some rather amazing claims are made, and not all of them about the physics of chocolate. To be fair, it's impossible to know if the quotes attributed to Rick Mast are accurate or whether the reporter took a liberal interpretation. Either way, the site, which encourages visitors to "rethink" science [sic], is presenting a revisionist version of chocolate physics.
"... raw beans have a much higher acidity level so it’s a more botanic flavor,” Mast said. “Roasting brings out other flavors to balance out the acidity.” The bean’s sugar and protein molecules gain energy in the higher temperature, and that increased activity leads to new atoms coming together and new molecules being formed."
There is so much unnecessary obfuscation in the above paragraph I don't know where to begin. Sugar and protein molecules gain energy creating new atoms? Okay, the beans heat up and chemicals in the chocolate change. Why not give the compounds names? Pyrazines, furans, esters, and ketones are among the classes of compounds formed during roasting, Rick, via processes knows as the Maillard reaction, Strecker degredation, and pyrolysis/polymerization, among others. It's science, not sex education, you can be explicit - the more explicit the better - with chemical names and processes, they are not pornographic, are they? Are they too explicit for young scientists' ears?
Furthermore, the flavors created do NOT directly balance out the acidity. Which acid? Acetic or citric? Some of the acetic acid evaporates out [during roasting], but enough remains so that the Dutch had to invent alkalization to neutralize it (oops, that's history, not physics). Conching does reduce acidity among other things (and arguably, the Mast Bros do not conche properly if at all) - and conching effects acetic acid more than citric acid which is why some chocolates have bright fruity notes and others don't. Fruitiness is not a generally-recognized flavor trait of alkalized chocolate, however.
"... For that to happen, the particles have to be just a miniscule [sic] 20 microns across (for comparison, the width of a strand of hair is 50 microns)§. The grind “is still acidic until all the sugar crystals have slowly emulsified with the cocoa butter so it tastes like one thing"
I am sorry. Could. Not. Stop. Laughing. The chocolate is still acidic until the sugar has emulsified with the cocoa butter? No. That's not the way it works.
First off, chocolate is not an emulsion. Chocolate is a suspension of particles in fat. Emulsifiers are used to reduce the surface tension of the fat molecules so the chocolate flows more easily. There is no physical process (and no chemical process) that I am aware of that reduces the acidity in chocolate by simple grinding, emulsification or no. There is a reason why the chocolate is just so bad.
After eight years, Rick still appears to know very little about the real science - physics and chemistry - of chocolate. To give him some benefit of the doubt ... maybe he does know the science but chooses not to communicate it clearly. I don't know - but the end result is the same.
§ - Or maybe not. According to Wikipedia ( https://en.wikipedia.org/wiki/100_micrometres) the average width of a human hair is 100 microns. Footnoted as: ^According to The Physics Factbook, the diameter of human hair ranges from 17 to 181 µm. Ley, Brian (1999). But - maybe red beard hairs average 50 microns? Yeah. That has to be it.
[Note: edited to fix typos on 11/21/15.]
clay - http://www.thechocolatelife.com/clay/
updated by @clay: 11/21/15 02:03:41PM