A Coffee Stain Hack for Clothing
Here is a coffee stain cleaning hack that you can use toward cleaning that errant drop or catastrophic spill of coffee on your clothing.
Have you ever wondered why coffee leaves a particular ring of stain on a flat surface like a desk or tabletop whereas other beverages do not? It has to do with both chemistry and physics.
It turns out that as a drop of coffee drop dries, the outer edges being thinnest, dry first and cause a flow of liquid from the center to its borders. In the process, the flow carries relatively large suspended particles from the coffee to the droplet’s edge until all of the water has evaporated away leaving the characteristic dark ring and lighter color center. Presumably, other beverages have smaller and chemically water-soluble particles to it that are either are not as visible and/or are not carried to the edge of a drying droplet.
Aside from this bit of coffee trivia, because coffee stains are a natural consequence and annoyance of drinking coffee, research has been done to investigate why coffee stains so easily and how the stains can be removed.
According to a paper published in the Journal of the American Oil Chemists’ Society, researchers have determined that stains on clothing made of polyester, cotton and nylon are due to water-soluble and acidic colored substances (those suspended coffee particles mentioned earlier) found in the coffee we brew. And, that the permanence of staining is dependent upon the nature of the fabric with polyester having the least affinity for coffee staining, cotton coming in second, and nylon coming out on top.
The reason for the differing degrees of staining is due to the acidic nature of coffee and both the ionic and non-ionic interactions that occur between those acidic coffee particles and molecular makeup of the fibers in the fabrics.
The point of all of this is that the following hack recommended for removing coffee stains from clothing is actually based on science, where researchers recommend that due to the dominantly acidic character of coffee stains, an alkaline medium (non-acidic) is needed for the removal of coffee stains.
In a recent article on the website food52 by Karen Lo about the best way to remove coffee stains from clothing—based on her experience from recommendations made by the University of Illinois—she developed a process that works.
According to the University of Illinois, you will need the following items:
• Liquid hand dishwashing detergent (an alkaline solution)
• White vinegar
• Rubbing alcohol
• An enzyme presoak product
• Chlorine bleach or oxygen bleach (warning: never mix chlorine bleach with ammonia or other cleansing products as dangerous fumes may result)
The University Extension's process to follow entails the following steps:
1. Soak the soiled garment for 15 minutes in a mixture consisting of one quart of lukewarm water, one-half teaspoon liquid hand dishwashing detergent and one tablespoon white vinegar. Then, rinse.
2. Sponge with rubbing alcohol, using light motions from center to edge of stain.
3. Soak for 30 minutes in one quart of warm water with one tablespoon enzyme presoak products.
4. If color stain remains, launder in chlorine bleach if safe for the fabric, or in oxygen bleach.
Ms. Lo’s process using the same ingredients:
1. First, flush the stain with cold running water (as heat will set the stain into the fabric), washing out as much of the stain as possible.
2. Then use liquid dish detergent over the stain to create a lather.
3. Next, use white vinegar to rinse out the soap, and usually, at this point, the stain is gone.
4. Wash the clothing afterward as you normally would.
Caveats to her method recommend that for a more serious stain is that after the vinegar rinse step, use a sponge to apply rubbing alcohol to the stain, working from the center. This then is supplemented with a before-launder step of soaking the stain in one quart of warm water with a tablespoon of enzyme.
As you can see, the coffee stain removal hack has a scientific basis and merit for the next time you spill your coffee—as well as fodder for your next “coffee talk” with a friend.
Timothy Boyer has a Ph.D. in Molecular and Cellular Biology from the University of Arizona. For 20+ years he has been employed as a freelance health and science writer. Timothy continues writing about science with a focus on the connection between coffee and healthy living. For continual updates about the benefits of coffee on your health, you can also follow Timothy on Twitter at TimBoyerWrites.
Image source courtesy of Unsplash, Photo by Tamara Bellis
“Coffee stain on textiles. Mechanisms of staining and stain removal” Kissa, Erik; J. Am. Oil Chem. Soc. 72, 793–797 (1995). https://doi.org/10.1007/BF02541027
Stain Solutions: Coffee (no cream) Washable fabrics; The University of Illinois Extension.
“This Is the Best Way to Get Rid of a Coffee Stain” by Karen Lo for food52 July 27, 2020.