The Eggshell Hack That Will Actually Improve Your Coffee

It turns out that eggshells can serve other purposes besides frustratingly falling into your omelettes and ruining your fancy breakfast attempts. They're packed with minerals and great for compost, writes Margaret Roach for The New York Times. And, they make your coffee less bitter.

At first mention, it might sound unpleasantly crunchy, but it's a long-practiced brewing trick. Some people go wild for acidic coffee — but if you prefer a mild, smooth blend, crumbling an eggshell into your coffee grounds before brewing your coffee can soften the acidity in your morning cup, according to Good Housekeeping. Once you're done brewing your pot, GH adds, "The spent coffee grounds, eggshell and bio-degradable filter are then conveniently ready for the compost pile."

The average eggshell is rich in calcium carbonate — in fact, that's its main ingredient. That's why eggshells make for wonderful compost materials, and that's what allows the shell to alter your coffee flavor. Calcium carbonate, an alkaline material, easily absorbs acidity, allowing it to take some of that sour, sharp flavor out of your coffee while leaving it strong and flavorful, explains America's Test Kitchen.

Some have gone further than sprinkling some eggshells into their drip machine: In some parts of Minnesota, it's not unheard of to use an entire egg — yes, yolks and whites all beaten together. Before you cringe at the mental imagery of a sunny-side up egg floating around in your coffee mug, note that the egg is folded into the coffee grounds before the mixture is boiled with cold water.

As a child, Joy Summers watched her grandmother do it all the time. The cup of coffee turned out smooth and flavorful, Summers explains for Eater. The tradition, known by some as "Swedish egg coffee," is said to have formed at the hands of Scandinavian immigrants adjusting to life in the Midwest. The result is a clarified, smooth cup of hot coffee, according to The Spruce Eats. As Summers explains, the tradition isn't so easy to find at your local coffeehouse, but it's still held dear in northern Minnesota as a sign of culinary genius.