Rob Hoos’s Book (cont.)

A few people on the home-barista forums have attempted to encapsulate the important points of Hoos’s book in a very succinct and simple fashion. I find this very useful as I think Rob’s many references to the myriad compounds of chemical reaction drawn from the vocabulary of physics and chemistry tend to obscure the basics of what us home roasters need to know to have more control over our roasting. I’m not against learning the physics and chemistry behind the roast but I doubt that a book about modulating the flavor of coffee through roast profiles is the place to take it on. Furthermore, I’m not sure that Hoos is the best person to do it. Here I’m quoting a distillation of Rob Hoos’s book and Rob’s reply to that attempt:

From Keno

The gist of [it] can be summed up, I think, fairly simply (like Rao’s book in terms of his three commandments) in the following two principles:

  • Longer ramp time from yellow to FC (or MAI time as Hoos calls it) promotes body and complexity
  • Development is a balancing act, too little development leads to bitter and vegetal flavors, while too much development time leads to bland flavor with low acidity

There are a few other points that are elaborated on but these are the two that seem to be firmly based on his roasting experiments and cupping tests in which MAI time and development time are varied with a few different coffees.

“Your summary of the book is a decent one. My largest goal in developing the book was to try and break down the roast into measurable segments that could be independently affected and adapted to create nuanced (and sometimes blatant) differences in the way the coffee tasted. When going through this process I basically ended up with 5 zones of control that I could change relatively independently in order to dial a coffee in to the flavor profile I was hoping to get. 1.) Time from the beginning of roast to the beginning of chemical reaction (ie color change), 2.) From the beginning of chemical reaction to the beginning of first crack, 3.) From the beginning of first crack to the end of the roast, 4.) The entire length of the roast, 5.) The degree of caramelization and pyrolysis. Then (through research and experimentation) I determined how changing those one way or another (as independently as possible) affected the cup. The ramp from yellow to fc, and the time from fc to drop were documented with specific experiments, and the others are referred to through less experiments (though they are pooled from my roasting and cupping experiences as well, just not documented in the same way).”

Author: korkiley

Systems Administrator at University of Vermont (retired as of 7/1/2012) Married Favorite Activities: Condor Glider Online Competition, Developing web sites, making espresso, and keeping a blog

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