Starbucks alone discards 210, 000, 000 pounds of used coffee grounds each year. Heck, our household produces about 76 pounds a year (quick and dirty estimate, after weighing the morning's wet grounds). Almost all of the grounds are discarded to landfills after one use. This practice is staggeringly inefficient. “Used” coffee grounds still contain a treasure of resources, if only we would learn how to make use of them.
There are a number of ways that one person or a family can remove some, or most, of their own grounds from the waste stream, and at least one potentially commercial application. I have not personally tried all of these, but I present them for your experimentation.
Ways to reuse used coffee grounds for your garden/ plants:
1. Add the grounds (filter too) to your compost pile. Coffee grounds contain nitrogen, phosphorus, and potassium. They are slightly acidic, which will benefit most soil types. If you are growing acid-loving plants such as azaleas or rhododendrons, they will be happy to have the grounds applied directly around their base. The texture of the grounds in your compost will ammend and help to aerate the soil.
2. Use them as a pest deterrent. Sprinkle used grounds around plants which slugs are likely to attack, such as hostas. Slugs don’t like crossing the rough surface. Of course, it’s not as effective as diatomaceous earth, but it’s much cheaper, and easily replenished. Supposedly, ants don’t like to crawl over them either, so a ring of grounds around a patio space which is overrun, may lessen the problem.
3. Top off the soil of houseplants with some used grounds mixed with dirt. I often wonder where the potting soil disappears to, don’t you?
Ways to reuse used coffee grounds in/ around your home:
4. If you have an oil spill on the garage floor, dried used grounds will absorb the oil and the odor. The Twisted Limb handmade paper company (Bloomington, Indiana) made an old engine-repair shop odor free in 48 hours by this method.
5. Use them as an abrasive cleanser for pots and pans. They work as well as many detergents, don’t cost anything, and are safer for the environment. You can still compost them after washing the pans.
6. De-ice the steps or driveway with used grounds. They are not harmful to plant life the way that salt is.
7. Keep a container in the refrigerator or freezer to eliminate odors.
8. Add a drop of any extract you like- vanilla, almond, etc- to a cup of dried grounds. Wrap this in a porous cloth (cheescloth or a used piece of stocking), and tie the top, to make a pomander for your closet. It will absorb shoe and sweat odors.
9. Pour a cup of coffee grounds and four cups boiling water down a smelly drain to deodorize it. (Don’t do this too often with a septic system, as introducing a lot of solids will cause problems)
10. You may be able to cover scratches on dark furniture by steeping the grounds to develop a colored liquid. Apply to scratches with a cotton swab.
Personal uses for used coffee grounds
11. Use as a facial scrub. The grounds act as an exfoliant.
12. Rub some into your wet hair, and then rinse for more luster and shine (and coverage of some gray?). This may help prevent dandruff.
13. Keep some by the kitchen sink to deodorize your hands after cutting onions or other smelly foods.
14. One possible use is as a treatment for cellulite. Personally, I don’t think anything works to reduce those nasty lumps, but supposedly this helps. You must use caffeinated grounds for this, as the caffeine is a stimulant and a diuretic. This is purported to increase blood flow to the area. Make a poultice of grounds mixed with lotion or olive oil. Apply topically to the areas of cellulite, and leave in place for at least one minute before removing. It’s probably best to do this in the tub or shower, as it could be really messy.
15. As a fiber additive to foods. The grounds usually need to be reduced to an even finer consistency, but they can then be added in place of some of the flour in appropriate recipes. Chocolate baked goods are suggested- mocha is almost always a winner. The author of the article, "Recycle Coffee Grounds, " says that he has personally added wet grounds, without further grinding to a powder, to oatmeal cookies and had such success that friends asked for more.
Other home uses for used coffee grounds
16. Rub some used grounds into the coat of your dog. This is supposed to deter fleas and ticks from making a home there, and possibly give the animal a shiny coat.
17. Boil grounds with some cloth, or soak papers in grounds to use them as natural toned dyes. (Note, wash any clothing dyed this way separately.)
Commercial uses for spent coffee grounds
18. In December of 2008, according to Science Daily, researchers at the University of Nevada-Reno announced that they had developed a method of extracting the oil from used grounds and converting it to biodiesel fuel. Beans once used to make coffee still have 10-11% oil content. This is comparable to many plants such as soy or rapeseed. After extracting the oil, the byproduct could still be composted. The group announced plans to build a pilot plant. However, as of April of 2010, Missouri University claims to be the only school studying this technology. In the Missourian, they explain that the current focus is to eliminate the costly step of drying the grounds from the extraction process. This would be an ideal way to recover yet another product from the waste stream.
Can one family really make a difference in reducing waste? I’ve taken on a goal to not put any coffee grounds from our house into the trash this year. Most will go into the compost, but I’ll try some of the other uses mentioned above.
Ten households times 76 pounds is 760 pounds. Just 26 households, using about the same amount of coffee, could keep a ton of coffee grounds from landfills, with no additional cost to themselves, indeed they would experience some economic benefits.
This sounds possible!
Also see "Used Coffee Grounds Could be Viable Source of Biofuel"