Jim, I like your assumption that Godfather implies old-school Italian and robusta. Makes sense to me!

This is what Fratello's website says:

Espresso: Godfather
Region: Guatemala, Sumatra, Nicaraguan, Brazil and Honduras
Roast Profile: Agtron 39

I don't see any robusta-producing regions in there. Also the medium-dark roast level shouldn't carry an extraordinary amount of caffeine.

I was going to suggest titrating with D+Caf caffeine test strips to determine the amount, but this Popular Mechanics article suggests that the strips can work to tell regular from decaf but won't be useful in determining the amount of caffeine present.

I'm not sure I've described all of this clearly enough.

I remember hearing or reading somewhere that Godfather contains Robusta. It consistently has more caffeine than the Rocket Brand. That's not in question.

What I have noticed is that, the Rocket Brand seems to have significantly more caffeine than usual. To give some background, when I order the Rocket Brand, I get 5lbs (within 3-4 days of roasting), and I freeze it according to the instructions I've read here (tape over the 1 way valve, place bags in a ziploc, place at the bottom of the deep freeze, and defrost a week's worth at a time.). The last shipment I received seemed to have far more caffeine than usual, on par with the Godfather blend.

Since it takes nearly a month for me to use up all 5 lbs, this observation was not made based on one afternoon's consumption, but over a month of drinking the coffee. Clearly, this past month the coffee seemed to be more caffeinated than previous months (Remember, this batch had a chance to age much longer than usual). Therefore, I think it's safe to rule out things like stomach contents, and other short term fluctuations.

As I admitted before, it's more plausible that the effects are the result of a change in the blend, or other factors that may be affecting me personally (I have been under a lot of stress lately. A few months without playing any gigs has meant very little income, and has left me wondering whether it's time to find a day job again.).

Nonetheless, I posed the question as a matter of curiousity.

another_jim wrote:AFAIK, caffeine is chemically stable, while the flavor compounds oxidize. So conceivably, the amount of caffeine per unit of taste would rise with age. However, I don't know if such a ratio makes sense.

This is precisely my question. Thank you for wording it much more ably than I did. "Does the amount of caffeine per unit of taste rise with age?"

I came across this looking for more info on this. My coffee supplier/roaster told me that caffeine definitely does continue to develop with age, so an older coffee will contain more caffeine, so your intuition/observation probably is based in fact.
More I do not know (yet).

Hello,
Having a chemical engineering degree I can certainly tell you that all conditions being equal (time, pressure and temperature) you will not extract more caffeine from old coffee. While grinding finer does expose more surface area it also exposes more surface area to other compounds that would be extracted.
Ketones are what are responsible the flavours we taste and the ratio of these to caffeine is going to be irrelevant. As coffee ages it oxidizes and the ketones will oxidize into a different compounds, they will not simply disappear. These other coupounds may or may not be water soluble or they may be lipid (fats and oils) soluble. These new compounds will then be drawn out with either the coffee oils or directly into the water. If they are not soluble at all they will simply remain in the bean.
The amount of a given compound that will dissolve into the water is determined by the solubility of the compound and the conditions under which it is extracted. Therefore, since you have not changed the conditions under which you are extracting your coffee grounds there should be no more caffeine as coffee ages unless you do actually extract it under more pressure or for a longer pull.

Hope that helps. So like other said it is probably a slightly different mix of beans to match what is seasonally available and relative flavour profile of the blend.

On an interesting note it is the pressure of the extraction that cause espresso to have it's unique flavour profile. The pressure is an atmospheric condition that makes the coffee oil water soluble thus pulling out literally hundreds of ketones from the bean that are only lipid soluble. These lipid soluble ketones would otherwise never be tasted using conventional methods. Fascinating stuff.

Lubby wrote:Having a chemical engineering degree I can certainly tell you that all conditions being equal (time, pressure and temperature) you will not extract more caffeine from old coffee. While grinding finer does expose more surface area it also exposes more surface area to other compounds that would be extracted.
Ketones are what are responsible the flavours we taste and the ratio of these to caffeine is going to be irrelevant. As coffee ages it oxidizes and the ketones will oxidize into a different compounds, they will not simply disappear. These other coupounds may or may not be water soluble or they may be lipid (fats and oils) soluble. These new compounds will then be drawn out with either the coffee oils or directly into the water. If they are not soluble at all they will simply remain in the bean.
The amount of a given compound that will dissolve into the water is determined by the solubility of the compound and the conditions under which it is extracted. Therefore, since you have not changed the conditions under which you are extracting your coffee grounds there should be no more caffeine as coffee ages unless you do actually extract it under more pressure or for a longer pull.

I'm dazzled. (This could be total BS for all I know, but it sounds really impressive.)

Lubby wrote:So like other said it is probably a slightly different mix of beans to match what is seasonally available and relative flavour profile of the blend.

I agree, this is definitely the more plausible explanation.