Caffeine

This is why the world produces more than 16 billion pounds of coffee beans per year. It’s actually an alkaloid plant toxin (like nicotine and cocaine), a bug killer that stimulates us by blocking neuroreceptors for the sleep chemical adenosine. The result: you, awake.

Water

Hot H₂O is a super solvent, leaching flavors and oils out of the coffee bean. A good cup of joe is 98.75 percent water and 1.25 percent soluble plant matter. Caffeine is a diuretic, so coffee newbies pee out the water quickly; java junkies build up resistance.

2-Ethylphenol

Creates a tarlike, medicinal odor in your morning wake-up. It’s also a component of cockroach alarm pheromones, chemical signals that warn the colony of danger.

Quinic acid

Gives coffee its slightly sour flavor. On the plus side, it’s one of the starter chemicals in the formulation of Tamiflu.

3,5 Dicaffeoylquinic acid

When scientists pretreat neurons with this acid in the lab, the cells are significantly (though not completely) protected from free-radical damage. Yup: Coffee is a good source of antioxidants.

Dimethyl disulfide

A product of roasting the green coffee bean, this compound is just at the threshold of detectability in brewed java. Good thing, too, as it’s one of the compounds that gives human feces its odor.

Acetylmethylcarbinol

That rich, buttery taste in your daily jolt comes in part from this flammable yellow liquid, which helps give real butter its flavor and is a component of artificial flavoring in microwave popcorn.

Putrescine

Ever wonder what makes spoiled meat so poisonous? Here you go. Ptomaines like putrescine are produced when E. coli bacteria in the meat break down amino acids. Naturally present in coffee beans, it smells, as you might guess from the name, like Satan’s outhouse.

Trigonelline

Chemically, it’s a molecule of niacin with a methyl group attached. It breaks down into pyridines, which give coffee its sweet, earthy taste and also prevent the tooth-eating bacterium Streptococcus mutans from attaching to your teeth. Coffee fights the Cavity Creeps.

Niacin

Trigonelline is unstable above 160 degrees F; the methyl group detaches, unleashing the niacin—vitamin B3—into your cup. Two or three espressos can provide half your recommended daily allowance.