That bag of used coffee grounds headed for the trash may have one more job before it leaves the house: helping fight the weird smell lurking in the garage. Coffee grounds contain a porous structure that can adsorb certain odor-causing compounds, giving yesterday’s coffee a surprisingly useful second act.
That does not mean a bowl of grounds can magically erase gasoline fumes, mildew, paint odors, or every other garage aroma known to humankind. It can, however, provide a cheap way to tackle ordinary stale smells, especially when the grounds go into the garage dry, and a homeowner also deals with whatever causes the odor in the first place.
