I have a question for those of you who measure density of green coffee. Have you noticed any relationship between green bean density and roasting level for espresso? My assomption would be to roast darker for lower density bean and roast lighter for higher density green bean. Does that make sens?

Not really. Roast level doesn't really coordinate well with bean density, other than the amount and timing of the heat you provide to the beans. Denser beans take more time for heat to penetrate, so should be roasted a bit warmer. Else they don't get to the level you wish at the right time.

mfortin wrote:My assomption would be to roast darker for lower density bean and roast lighter for higher density green bean. Does that make sens?

Why? Roast level (in terms of bean color as measured by Agtron number) would seem to be more a matter of preference than anything as roast level affects aroma and taste for a given bean. Agree with billsey that denser beans (eg washed high grown hard beans) will require more heat to roast than less dense beans (eg, Brazil natural) to penetrate the inside of the bean.

I reckon should be the other way around. Higher density beans will be harder to grind out in light roast and will need high quality grinder to bring out all the flavor at lighter color. it will need to be darker to make it soluble

Lower density beans will be easier to grind in light roast and will be more soluble as well in darker.

I believe the roast level should be based on the coffee or cup flavour though rather than density.

Density shouldn't determine roast level as you can't fix a roast profile based on one variable. . Roast level should always be dependent on the drinker's preference and matched with the potential of the coffee.

There are ways to fully develop coffee at any roast level. It's just that denser coffee may require more time and/or heat for full development. Or not if coffee quality is that excellent.