Mixing coffee grounds with bicarbonate of soda is a surprisingly effective method to absorb odours and deter pests. Leftover coffee, with its granular texture, has the ability to absorb smells, while bicarbonate of soda is known for its neutralising power.
Households can mix the two ingredients in a bowl and use them for different purposes around the house and garden; place them in the fridge, bin or car to neutralise odours, or keep them on the patio or windowsills to deter pests. Gardening experts at WWNursery recommended this method to repel insects.
Most insects, including spiders and mosquitoes, have a very strong sense of smell, and dislike the strong smell of coffee grounds.
The gardeners said: “As unlikely as it sounds, the solution is coffee grounds! Coffee grounds are a safe and effective way to keep pests away. Coffee grounds can help repel not only mosquitoes but also other annoying insects like wasps and bees.”
According to experts at TheKitchn, coffee contains nitrogen, which helps neutralise odours rather than simply covering them up, just “like baking soda, but with a much cosier scent”. They explained: “The grounds naturally absorb all kinds of funky smells and leave behind a very light coffee aroma.”
The experts suggested: “While I used this trick for my kitchen trash, you can easily use it all over your home, from the fridge or freezer to soak up food smells, to your car if it’s starting to get musty, or even near litter boxes and pet areas.”
The US Department of Agriculture added: “Sprinkle fresh coffee grounds or baking soda loosely in a large, shallow container in the bottom of the refrigerator and freezer.”