Introduction: 11 Unusual Uses for Coffee

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Every coffee drinker knows the feeling they get when they have their morning ritual of a hot strong cup of coffee. Mmmmmm, just saying the word makes me smell it in the air; coffee. As a longtime coffee consumer and avid caffeine-scientist I've seen my way around more than a few pots of potent, percolating brain juice. We all know the great benefits of coffee, it's:

  • Hot
  • Caffeinated
  • Awesome

But did you know that coffee has a life outside of being a tasty bevvy? It's true! Coffee grounds can continue to be useful after you've had your morning fix and can work in some interesting ways. So, save those beans and find 11 unusual uses for coffee!

Step 1: In the Garden

Spent coffee grounds can be mixed with lye to make a great composting agent, you can even throw in the coffee filter, too!
Worms in compost like to eat the bacterium that grows on the facets of coffee grounds, though the grounds themselves are a a food source it also adds grit to the worms' digestive system allowing them to digest better.

Small amounts of coffee grounds can be added directly to top soil, especially on plants that like high acidity in the soil like azaleas or roses. Coffee is high in nitrogen, calcium, magnesium, potassium and other trace minerals, spreading around a thin layer of coffee grounds on your soil will allow a slow release of these minerals into your plants.

Be aware of which plants like acidic soil (roses), and which plants don't (tomatoes).

Insect Repellant:
Coffee has a very strong odour which many insects and animals do not like. In addition, it's been suggested that mosquitoes, ants, slugs and maggots all dislike the acidity of coffee and will stay away from areas where there is high concentration of acidic soil.

Step 2: Pet Repellant

Pesky neighbour's cat or dog always up in your flowerbed? Sprinkling coffee grounds along with other powerful odour-emitting substances can keep those animals away. Most animals' sense of smell is much greater than ours, and while coffee that may smell great to us can smell very unpleasant to a hyper-sensitive-olfactory feline.

Used coffee grounds can be mixed with orange peels (or other citrus) and spread around flowerbeds for an inexpensive pet deterrent. This potent concoction was enough to drive the cat in this picture away, after a brief sniff he couldn't get away fast enough!

Step 3: Aromatic

Instructables member noahw made a coffee air freshener, "enjoy that great coffee bean scent whenever and wherever you like."

You can easily make your own with a pair of ladies stockings and fresh ground coffee. Simply double-up the stockings, fill with coffee grounds and then tie off.

Step 4: Palate Cleanser

You may have noticed that many perfume counters at department stores have a small dish of coffee beans nearby (and if they don't have them, they should). These coffee beans are there to 'cleanse your palate' (olfactory). The reason you want to smell coffee beans between perfume samples is that when testing out powerful aromatics it can get hard to discern one scent from another. The strong odour of coffee beans excites different areas in your olfactory, allowing a more sensitive smell for the next perfume you want to smell.

UC Berkeley scientist, Noam Sobel, writes in his article "Influence of Smelling Coffee on Olfactory Habituation":

Smelling coffee aroma between perfume samples, as compared to smelling unscented air, actually works. The perceived odor intensity of the perfume from sample to sample stayed the same after smelling coffee aroma while it decreased when smelling air between samples. The pleasantness of the perfume, however, was similar after smelling coffee or air.

So grab those beans next time you're sampling perfumes or colognes and give your nose a break!

Step 5: Fridge Deodorizer

Borrowing noahw'sair freshener idea, I found that you can use coffee to help reduce refrigerator odours and food prep smells, like onions or other strong smelling food.

Make a sachet of ground coffee and leave in the back of the fridge for a few days, the sachet should help absorb some of the strong food odours and emit a pleasant coffee aroma.

Step 6: Meat Rub

We all know coffee is great for breakfast, but what about dinner? Try a coffee rub on your next steak dinner for a unique flavour experience! I toasted fresh coffee grounds under a hot broiler for about 30 seconds, shaking often to prevent burning. The toasted coffee was then added with other steak spices and rubbed into the steak and left to marinate for a few hours in the fridge.

Cook steak as desired.

Step 7: Fabric Dye / Wood Stain

Coffee's dark colour makes it a good choice for giving fabrics that worn-look and wood an aged patina. You're not going to end up with a very dark dye or stain, but you will get a unique, weathered look. Depending on number of applications and type of material the coffee is applied to this method of dying and staining can produce some effective results.

Fabric Dye:
Brew a regular pot of coffee and completely immerse the fabric of choice into pot, you may need to place a small weight on top of the fabric to stop it from poking out of the coffee while it's soaking. Allow fabric to dye for 24 hours (or longer), then rinse fabric and let air dry. The result is a browny,off-white colour; giving the fabric an aged look. Try a few different strength of coffee brews, or length of time fabric is submerged to achieve different shades.

Wood Stain:
Brew a strong pot of coffee and place the grounds back into the pot, allow to slightly and then apply to untreated wood. The coffee will stain the wood a slightly darker stain, but don't expect very dark results. Leaving a the coffee grounds directly on the wood will result in a darker stain.

Step 8: Paint

Artists and crafters have used coffee and tea as a form of 'paint' for ages. Regular brewed coffee can be brushed onto cardstock and will dry with a faded, browny, textured look. With repeated applications you can build up your image and create depth.

Make sure to take a sip between brush strokes.

Step 9: Cleaning Abrasive

Used coffee grounds can be used as a cleaning abrasive. Simply save up your coffee grounds and scoop some into your next dirty pot or pan before hand washing, the absorbent grounds are perfect for greasy pans and the small jegged edges of each ground helps in cleaning even the grossest of dishware.

Step 10: Facial Exfoliant / Faux Beard

Facial Exfoliant:
Coffee grounds are abrasive enough to scrub with, but are soft enough to be used on your face. Gently massage a small amount of spent coffee grounds into your face to use as an exfoliant. The sensation was like rubbing sand into my face, and not unpleasant. My skin was left feeling smooth, tingly and with an espresso aftershave aroma that would make Juan Valdez blush.

Faux Beard:
Feel free to get carried away and give yourself a fearsome coffee-beard while you're doing the exfoliation.

Step 11: Breath Freshener

All out of mints? Sucking on a whole roasted coffee bean can work in a pinch.
Just pop a whole bean in your mouth on the way out the door and you'll have fresher breath than before in no time!

Have you got another unusual use for coffee? Leave your suggestions in the comments below!