Decaf coffee surprise

Riddle: What do decaf coffee and skunk musk have in common?

Answer: High concentrations of mercaptans

Shuffling through a major health food store, I turn down the coffee aisle and pass the open bins of beans. I always swing through for the nose candy before I hit the check out. But this time I stop in my tracks. One of the bins is labeled “decaf French roast” but smells like Pepe Le Pew.

What do decaf coffee and skunk musk have in common?

“Skunk!” I point. The woman next to me grabs her kid and pushes her cart briskly down the aisle.

I nose in closer to the bin to pinpoint exactly what is going on in there. I sniff it like a dog at a fire hydrant. Nowadays, I catch myself doing this a lot.

This particular bin contains all the notes a good coffee should–smoke, chocolate, tobacco, dark fruit and spice–but they are in the wrong order and topped with skunk. I sniff the nearby bins just to be sure. Yep, sure. This bin is a Rossini opera sung in pig latin.

I ask the clerk about it. He shrugs his lanky 20-something shoulders and suggests I choose another variety. But this is the only decaf French roast. Not that I want to drink it; I drink tea. I want to know.

Turns out that coffee naturally contains about 400 chemicals, including furfuryl mercaptan, a compound in the same extended family as skunk musk’s butyl mercaptan. Furfuryl mercaptan lends coffee a roasted, meaty aroma. Much of it gets lost in the decaf process, so it’s added back in later to make the decaf smell more enticing, according to David J. Rowe, author of the book Chemistry and Technology of Flavors and Fragrances. When the mercaptans are out of balance with the other naturally occurring aromatic chemicals in coffee–decaf gone wrong–it can reek of skunk.

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  1. I love the Daily Smell!

  2. Fascinating!

  3. I also love the Daily Smell! I have an above- average nose, although nothing like yours, and some days I feel like I don’t want to go out in public, because I can smell everyone too well! My sense of smell changes over the month along with my hormones. Maybe that’s why sometimes it is overwhelming. Did your super sense overwhelm you at first, and have you gotten used to it, or does it just make everything more interesting? Thanks for sharing your stories!

  4. My friends always told me I was crazy when I claimed fresh coffee grounds have a sort of skunky odor. Thanks for the explanation. I have always had a super-sensitive-sniffer and this topic fascinates me. I think my marriage ended mostly because I never liked my husband’s smell!


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