Why decaf takes longer to drip

Dear Matthew Alice: We drink both regular and decaffeinated coffee. We grind them to espresso fineness. But when we make the coffee, it takes twice as long for the decaf to drip through the filter. Why would that be? — Jittery, San Diego

The research elves in the Grandma Alice Homestyle Test Kitchen and Linear Accelerator Lab are up to their jerkins in wet grounds and cold java. We called in temp elves, ran three shifts round the clock, stocked emergency donuts to keep spirits up — but still we failed to duplicate the drip-through disparity. Any elves taking a break from drip-and-grind duty were herded to the phone banks to dial up coffee roasters, coffee processors, coffee sellers, people who can spell “coffee”...whoever. Even the eminencies at Starbucks in Seattle. We got a universal “Huh?”

Our conclusion...you’re hallucinating. But we’ll play along and pretend this really happens in your house. Assuming all other parameters are equal (same variety of beans, exactly the same grind, drip method, water volume and temp, same amount of finished product), the most likely explanation would have something to do with the fact that decaf beans have been soaked in water or chemicals before roasting to remove the caffeine.

Your decaf particles might cling together more in the filter, reducing the tiny air spaces required for quick dripping. Maybe decaf absorbs less water, so it produces more finished product and takes longer. Or maybe it’s because you make the decaf at night, and it only seems to take longer. Grandma Alice recommends you relax and have a nice cup of Postum.