Use ground coffee to deodorize lingering smells in your fridge. It's an effective way to neutralize strong smells and replace them with the warm scent of coffee.
The nitrogen in caffeine boosts the ability of the carbon in coffee to absorb foul odors. Unlike air freshener sprays, ground coffee doesn't just mask odors — it eliminates them.
This hack works just as well with unused, fresh coffee as it does with grounds that have already been brewed. However, there's no need to waste coffee, so put the used ones to use.
Leave the grounds out to air dry or roast them at a low temperature to speed up the process. You can use grounds that are still wet, but keep an eye on them for mold.