[Homeroast] Storage right after roasting

Mike Davis mldavis2 at sbcglobal.net
Tue Aug 19 12:49:11 CDT 2014

Both comments are correct - you cannot practically eliminate all 
oxygen.  The point is to minimize circulation to exiting CO2 gas which 
will create a positive pressure and carry some O2 with it, but of course 
not all.  And while the bean cell structure has been partially fractured 
by heat, nevertheless, the bean is still largely intact and what O2 is 
still left won't have much effect in the short (days) term.  It takes 
time for O2 to permeate the cell structure. Perhaps this is why some 
roasts are deemed better after a couple of days rest, and this idea is 
consistent with Tom's comments and from some blind tasting comparisons.  
I don't think anyone really knows why, exactly.  Coffee is so chemically 
complex that it would take a lot of lab work to compare and identify 
changing compounds.  I do it my way because it works for me.

And of course beans in the grinder are subject to oxygen as well. With a 
lid on the grinder the flow of air through the hopper is blocked and 
this retards oxidation to a small degree.  My grinder hopper will barely 
hold 1/2 lb. so that gets used up before significant deterioration takes 
place.  I keep my roasted beans in my AirScape until I transfer them to 
the hopper for the day.

Good discussion, guys, thanks!

Mike Davis

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