Re: figuring caffeine levels

On Sep 7, 12:08 pm, phreaddy <phrea...@xxxxxxxxx> wrote:
I'm trying to figure out how much caffeine is in a triple ristretto so
I can reassure my wife/guests/etc.

I found this caffeine guide from the Mayo Clinic, but it doesn't
address the triple ristretto issue.

http://www.mayoclinic.com/health/caffeine/AN01211

I assume a triple ristretto's cafeine level is NOT a straight
multiplication from a single shot, because you're not using three
times as much water, even if you are using three times the coffee. (My
understanding is that caffeine is one of the last things to be
extracted, not one of the first. Thus, French-pressed coffee will have
more caffeine than drip coffee, which will have more than espresso,
etc. Am I on the right track?

I go by Illy's reported studies, based on their scientific studies
(both theirs and third parties) - but I'm remembering these numbers
off the top of my head, so they may be +/- a few mg:

Arabica roasted: 1.2% caffeine by weight
Robusta roasted: 2.2% caffeine by weight

Espresso extraction: 70-80% of caffeine extracted under normal brewing
conditions*
Drip coffee extraction: 92-97% of caffeine extracted under normal
brewing conditions**

* double "ristrettos" extract less caffeine - caffeine is one of the
more resistant things to "leave" the ground coffee, so where 40-60mls
of water flow through 7g of coffee will extract 70-80% to produce a
30ml shot (some water stays in the puck, some goes back thru the
machine because of backpressure release), when 70mls or so goes
through 20g of coffee to produce a 30ml shot, less caffeine per g
would be extracted (see below). I'm estimating as low as 50% for a
ristretto style shot.

** drip, as Illy defined it, is a 6 minute pass through percolation of
a bed of coffee, and the continual water flow is what finally defeats
caffeine's resistance, and extracts almost all the coffee's stored
caffeine, leaving as little as 3% behind. Methods such as aeropress,
vacpot, clover, etc will produce significantly less caffeine in the
cup.

So:

1g coffee = 12mg caffeine arabica, 22mg caffeine robusta.

7g coffee (single shot, traditional, using arabica) = 84mg of caffeine
x .70 (lowest estimate for normal) = 58.8mg in a single shot.

14g coffee (double shot, traditional, using arabica) =168mg of
caffeine x .70 = 117.6mg caffeine in 60mls espresso.

20g coffee (pulled ristretto, using arabica, producing 30mls of
espresso or less) = 240mg x .50 = 120mg espresso, 30ml shot. (that's a
heckuva potent shot tho)

Basically double all the amounts, and subtract 10% for robusta shots.

Drip:

7g per 4 ounces brewed

8oz cup = 14g = 168mg caffeine x .92 (low end) = 154.56mg caffeine
12oz cup = 21g = 252mg caffeine x .92 (low end) = 231.84mg caffeine.

Again, double the amounts and deduct 10% for robusta. Most instant and
cheapo coffee is robusta, so that's a huge caffeine hit.

Mark

.

Relevant Pages

  • Re: figuring caffeine levels
    ... multiplication from a single shot, ... even if you are using three times the coffee. ... more caffeine than drip coffee, which will have more than espresso, ... Espresso extraction: 70-80% of caffeine extracted under normal brewing ...
    (alt.coffee)
  • Dracii din cafea - posedatilor !
    ... Coffee: The demon drink? ... Caffeine is the most widely consumed psychoactive substance on earth, ... And then there are all the health fears. ...
    (soc.culture.romanian)
  • Re: Coffee is number one source of antioxidants
    ... Coffee is a mild diuretic useful for BP lowering which is of interest ... >> On the other hand caffeine might raise blood pressure - it is not that ... > make most research findings false. ... comments on statistics are right on. ...
    (sci.med.cardiology)
  • Caffeine: Psychological Effects, Use And Abuse
    ... Caffeine: ... Its central nervous system stimulation can cause pleasant ... effects with improved attention and concentration at lower doses. ... of coffee? ...
    (misc.health.alternative)
  • Re: Coffee may reverse Alzheimers
    ... Coffee 'may reverse Alzheimer's' ... Drinking five cups of coffee a day could reverse memory problems seen ... in Alzheimer's disease, US scientists say. ... Previous research has also suggested a protective effect from caffeine. ...
    (soc.retirement)
Loading