Coffee Chemistry | The Skeptical Chemist

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Caffeine is a rather stable molecule owing to its aromaticity (ten π electrons within its 5,6 ring core). It can be extracted by passing soaked coffee beans through activated charcoal – this ‘caffeine extract’ can then be used in energy drinks and caffeine tablets while the beans sold as ‘decaffeinated’… a waste of good beans, if you ask me.

Chemical Stability. As mentioned earlier, caffeine being stable means it is difficult to break down as the bean is roasted. This results in very dark beans having only slightly less caffeine content than the starting unroasted bean. The majority of other chemicals – that give the aroma and taste characteristic of the bean – are broken down much quicker, that’s why very dark beans lose their coffee-ish taste and taste more like roasted carbon.

Lethal Dose of Caffeine. Okay, we’ll finally get to the part all of you have been waiting for – how much caffeine will kill you? Caffeine enters the bloodstream quickly and is an antagonist of the adenosine receptor in the brain, causes constriction of blood vessels and increasing blood pressure by blocking the effects of adenosine (vasodilation)². It is metabolized via the cytochrome P450 1A2 pathway in the liver into 3 metabolites, each with further physiological effects.

Caffeine is a rather stable molecule owing to its aromaticity (ten π electrons within its 5,6 ring core). It can be extracted by passing soaked coffee beans through activated charcoal – this ‘caffeine extract’ can then be used in energy drinks and caffeine tablets while the beans sold as ‘decaffeinated’… a waste of good beans, if you ask me. Chemical Stability. As mentioned earlier, caffeine being stable means it is difficult to break down as the bean is roasted. This results in very dark beans having only

Source: Coffee Chemistry | The Skeptical Chemist