Master Gardeners: Coffee grounds are for more than brewing coffee
Published 12:19 am Saturday, May 1, 2021
By Sheri Bethard
Orange County Master Gardeners
For those of you who do not compost, just starting to compost or are interested in composting, one of the best things for your compost and your garden is used coffee grounds along with even fresh grounds.
As most of you know the best use for “spent” coffee grounds is either as a soil amendment or in your compost pile/bin. By adding them directly to the garden soil or your compost, you are adding a small amount of nitrogen in. When you do add them, it is very important to mix them into the soil or compost, not let them sit as a thick layer in either one.
Plants will slowly take in the available nitrogen from the grounds over time and it also helps retain the soil’s moisture. Grounds contain the three major components of nutrients for plants and grasses to survive – N (Nitrogen), P (Phosphorus) and K (Potassium). There are also small amounts of micronutrients found in the grounds such as magnesium, copper and calcium.
There are tests being done to see the effect of coffee grounds on turf grass, sports fields and golf courses. They could improve how fertilizer preforms and would be a rival to peat moss for organic amendments along with being less expensive.
Other uses for grounds are:
- Odor neutralizer. They absorb and remove odors. Place an open container in your refrigerator, small cloth bag for gym bags and can help remove odors from your hands when used with soap
- Cleaning scrub. The abrasive quality helps on hard-to-clean surfaces, buildup in sinks and caked-on foods
- Exfoliating scrub. Now, don’t laugh but the grounds can be used as an exfoliant to remove dirt and dead skin cells. Mix with water and coconut oil and apply to skin, rub gently and rinse.
- Natural dye. Using grounds will dye cotton, linen rayon and other natural materials thus giving it an older or vintage look. You can even dye your hair with it.
- Furniture renewal. You can disguise a small scratch of scuff mark with a mix of one tablespoon coffee grounds and one teaspoon olive oil. Put some on a cloth and apply and wipe dry.
- Cosmetic purposes. For a long time, used tea bags have been used for dark circles under the eyes. Coffee grounds are just as good as they contain antioxidants and caffeine that will help the appearance of aging and shrink under-eye circles. Add water or coconut oil to used ground and apply under eyes being careful not to get any in your eyes. Relax for 5-10 minutes then rinse off.
- Did you know they are a meat tenderizer because of the natural acids and enzymes they contain helping soften meat? Add a few tablespoons of used grounds to your favorite rub 2 hours before cooking. It will add a darker, crisp crust to the meat. Using instant coffee or brewed coffee instead of water to chocolate cakes and chili can enhance their flavor.
Tests have been done using them as an insect or fire ant repellent, but they were not successful removing them.
There are many innovative products being made from either fresh or used grounds. Some include components in soaps, facial creams, yarn, fabrics, printing ink and even furniture.
Other parts of the coffee bean are recycled even before it comes to you in the form of grounds. When the “cherry” is picked from the trees, the shell has to be removed to expose the bean. These are used on the coffee farms frequently in compost. Once the shell is dried and processed it can be sold sometimes at a higher price than coffee and is used as tea-like infusions and making flour for cooking. When trees are pruned the remnants are also used in composting or turned into bio-char for a soil amendment.
Oils have also been extracted from spent coffee grounds and used in the production of biodiesel, mixed in with polymers to make household products such as cups and plants along with briquettes and fireplace logs.
While researching for this article, I was amazed at all the uses for spent/used coffee grounds. I am going to try some of the uses above myself.
For your horticultural questions, please contact our Hot Line at 409 882-7010 Tuesday and Thursday’s from 10 a.m. – 2 p.m, email firstname.lastname@example.org or post on our Facebook page Orange County Texas Master Gardeners.