bigabeano wrote:those are my thoughts exactly. but i'm not so sure about the importance of "aggressive" mixing in a french press or vac pot. any thoughts on its significance, other than perhaps accelerating extraction some?

Hi Scott,

I was looking for a mechanism by which the outgassing of CO2 could make a difference. The only thing I could come up with was that it might vary the surface tension on the coffee grains so as to cause them to wet unevenly. I remembered a piece in Jearl Walker's Amateur Scientist column in Scientific American years ago in which he wrote about Turkish coffee. If you make Turkish coffee in a lab beaker, you can see the sugar melt in the bottom layer. Only when the convection cells take the syrup up to the layer of coffee, in which you can see the grains of coffee surrounded by gas, will the coffee particles wet. When that happens, it suddenly changes the dynamics, and that's what accounts for the appearance of boiling when you do it in an Ibrik. I thought something similar might be happening here, and that if it was that more turbulence might affect it.

I know you did the experiment with a variety of coffees, but I have to imagine that the flavor profile made a difference, since more floral flavors are known to come from smaller and more volatile molecules. We also know from Jim and Abe's visit to George Howell that coffee ground two weeks earlier is only a pale shadow of its fresh-ground self, which puts an upper bound on the optimal time. I imagine that as this is explored, the optimal time will vary with both the brewing method and the coffee itself, and may vary with which part of the flavor profile the person tasting it most values, i.e. I hypothesize that the way a given coffee changes its flavor profile as it ages as whole bean is mirrored as it does so after being ground, only faster, and that the shift from more floral flavors toward more chocolate or wood will appeal to people at different points.

Best,
David

Seeing it advertised here on HB, I recently bought The Professional Barista's Handbook
By Scott Rao.

It covers well most information anyone could seek. I am an espresso home fan and find TPBH very interesting and informative. Scott covers Espresso, Coffee and Tea. Reading the work is fun and offers helpful information for where my level is today. Scott's well researched handbook will serve as a solid reference in the future and sits now on my kitchen cookbook and reference shelf.

I particularly appreciate the 2nd chapter on Espresso and would like to hear other's reaction to the book.

Santa brought me a copy and I've only read the first couple of chapters (and skimmed the rest) but I must say that I can echo the other reports here, its a fantastic book. The presentation, photography and writing style are really superb. This book is really a valuable resource to any home barista, beginner to pro. In fact I really think it will make the passionate beginner a knowledgeable pro faster than most other means.

If you "geeky" enough to be part of online coffee communities than this book is right up you alley, very highly recommended.

I also like and recommend it.

Count me in the "I got one for Christmas" camp, too. Really looking forward to reading through Scott's very nicely done work. Ain't the holidays fun?