There are numerous psychoactive chemicals in coffee - not just caffeine.
I haven't been able to relocate the source, but I read a number of years
ago that there a some particular ones present in robusta that aren't in
arabica or that are present in robusta in much higher concentrations
than in arabica.
This explained something I had experienced numerous times. When I had
switched to drinking coffee almost exclusively from 100% Arabica
sources, i.e., bringing my own to work rather then drinking office
coffee, I no longer got the "jitters" from drinking coffee. And when I
would be placed in a situation where the only coffee I could drink was
cheap coffee and I would partake, I'd get the jitters from just one cup,
even though I could drink my arabica all day without experiencing this.
I'd feel this within 5 minutes.
I have discussed this with many other people who then recognize that the
same pattern has happened to them.
As I have been exploring homeroasting over the past few months, my
coffee intake is very high. Although I sometimes can tell that I have
ingested lots of caffeine, I don't get that "jitters" feeling.
However, I haven't pursued any robusta to once again replicate that
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