Interesting new study article

Here's the background info on this:

For the past fifteen years or so, industrial roasters have been dissatisfied with either bean temperature or color as an indicator of how done the roast is. But rather than hiring me to sniff their smoke stacks ( ), they have been experimenting with "chemical noses" to measure the ratio of two volatile compounds, one that disappears during roasting, and another that appears. The trick is finding the right two compounds and the gear to measure them fast enough to act as a roast controller. This has been the source of several articles.

If they would just pay me the big bucks, I'd show them the answer buried deep in the Carl Staub article reproduced at SM: the magic compounds are the declining grassy smell and increasing caramels; the gear is a human nose.

I think 3/4 of the articles I quote or reference are Carl Staub

Interesting the probes are placed in a hole drilled into the bean and on the bean surface.