[edit] Here's a photo of the back of a bag of his "reference" Trung Nguyen S blend. It explicitly says that it has flavorings in it, including "coffee flavor". Omfg.<p><a href="https://imgur.com/a/KeSYq" rel="nofollow">https://imgur.com/a/KeSYq</a><p>---<p>I guess the guy had fun, but the conclusion is a few giant leaps away from the actual results. Many of his decisions and assumptions were entirely arbitrary, not well substantiated, and lacking just about anything approaching rigor.<p>His <i>reference coffee</i> is "A blend of Arabica, Robusta, Chari (Excelsa) and Catimor beans"[1], roasted in a special style, and brewed in one particular way with no mention of temperatures involved or any other variable that alters the outcome of brewing coffee.<p>Trung Nguyen coffees are as far as I know usually adulterated with chocolate and other flavoring either during or after roasting. This is not a bad thing. It smells and tastes goddamn fantastic and they are my favorite coffees in the world. But it's not exactly a good reference.<p>His <i>reference chart</i> includes only two of those bean types and specifically references green beans, not roasted beans, not butter roasted beans, and not beans roasted at any particular range of temperatures or durations.<p>He doesn't indicate that a <i>reference coffee</i> was chosen based on lowest wholesale cost, which might have been a reasonable decision factor for a street vendor, but rather just that it seems to be commonly available on the consumer market without regard for composition or lack of monopoly.<p>His <i>reference not-coffee</i> is only one of plausibly dozens of different not-coffee substances.<p>His <i>reference not-coffee solution</i> is based on approximately tasting like terrible coffee. Whaaaaaat.<p>And even if you choose to ignore any or all of the above, nothing about his method tests for <i>coffee</i>. Coffee is generically an extremely complex blend of varying volatile compounds, but specifically it is an infinity of different complex blends of varying volatile compounds. And his process doesn't actually test for any of them. It tests for some secondary characteristic that one mixture possesses, ability to change the color of iodine, but that one arbitrarily different other chemical does not possess to the same degree under the assumption that all real coffee changes the color of iodine the same and that all non-coffee also changes the color of iodine the same. These are exceptionally ridiculous assumptions.<p>[1] <a href="http://www.trung-nguyen-online.com/trung-nguyen-coffee-order.php" rel="nofollow">http://www.trung-nguyen-online.com/trung-nguyen-coffee-order...</a><p>> <i>Overall it sounds like a reasonable test for the amount of coffee in something</i><p>No, it really does not.<p>This is what happens when people think that "science" is synonymous with measuring shit.