How to remove tough tannin stains
Anyone involved in carpet cleaning often find success when removing coffee or tea spills — if the job comes relatively soon after the spill occurs.
But allow a few days to pass, and the coffee, tea or wine stain is one tough customer.
These stains appear to take up permanent residence in the carpet. Your most aggressive cleaning technique often shows limited success.
This technical bulletin will help you analyze the makeup of coffee, tea and wine stains and the best way to completely remove them.
Why so tough?
Coffee, tea and wine (and many other beverages that contain “tannins”, such as fruit juices) are difficult to remove because of the high temperature of the spill and added substances in the beverage (with the exception of wine and cold drinks).
Plain, black coffee removal is one thing; black coffee with added cream and sugar is another.
In addition to this, some decaffeinated coffees often have artificial colors added to give it a richer look. Other, organic and non-caffeine coffees also can have artificial colors added. Artificial coloring can be tough to remove.
When performing spot or stain removal with coffee or tea that has flavorings added, you often have to use spotters (typically alkaline spotting agents) for those substances in addition to the basic coffee spill.
And then there are the tannins in beverage spills. Tannins are found in beverages such as:
- Beer and other alcoholic drinks
- Fruit juices
- Tomato juice
- And more
Tannin is a natural occurring vegetable dye found in many plants especially grape skin, tea leaves, bark and stalk of vegetation. It is responsible for the “bitter” taste of red wine and some coffees — a good thing, as long as it isn’t spilled onto the carpet.
When coffee or tea or other beverages with tannins are spilled onto carpet, the heat of the beverage “opens up” the fiber and allows it to penetrate, at times penetrating through any fabric protection in the carpet. However, the better protection in the carpet, the better your chances of complete stain removal.
These hot spills bond with the fiber and removal is difficult, especially after a day or two have passed — or weeks or months, which can be the case.
(Remember: If you are called to clean a fresh coffee or tea spill, have your customer put a damp, white towel on the spot and weight the towel down. This will keep the spot damp and easier to remove when you arrive.)
What to do?
The first step of removal is to clean the spot or stain with a quality detergent, which will help remove added substances.
Do not use real soap, as soap can set the tannins or at least make them more difficult to remove. Although the cleaning industry uses detergents and not real soap, your customers may feel tempted to grab a bar of soap and use it on the stain. That”s a mistake.
After applying the detergent, work it into the spot or stain and allow dwell time; then extract the spot or stain.
What is left behind is probably a tannin stain.
Next, apply a tannin stain remover (tannin stain removers are acid-based detergents, which work by dissolving the tannin for easier removal), work it into the stain, and allow to dwell for several minutes. Extract the spot and inspect.
If you still have a stain, it’s time to use a color-safe bleach.
When the going gets tough…
There are two schools of thought with removing the remaining coffee or tea stain.
Some cleaners recommend using a reducing agent; another say an oxidizing agent is best.
Often, either one will work fine. The bleaching action of these products removes the discoloration.
Choosing a reducing agent (typically a powder) is smart, especially if you are in a hurry. Reducing agent action can be seen very quickly, while an oxidizing agent takes more time.
What works on one stain might not work on another. Have both classes of bleach on hand at all times. Use heat to activate the chemical, and if you are unsuccessful after several attempts, wet the stain with an oxidizing bleach, cover with plastic and allow dwell time up to 24 hours.
Caution: When using heat, especially from a clothes iron, you can remove carpet color. Be sure to monitor the bleaching action to avoid this.
When it keeps coming back
You removed the coffee or tea (or wine, etc.) spill and a day or two later you get a phone call telling you the spot is back — and perhaps even bigger.
Many spot and stain removal attempts leave some residue in the base of the fibers or the backing of the carpet. This then prompts “wicking”, or the upward movement of the substance to the surface.
As the carpet dries, the substance moves up the carpet fiber and then sits on the surface and dries. Most of the time, this is why spots come back.
Remember: The last part of the carpet to dry are the tips of the fibers, not the base.
Jeff Cross is the senior editor of Cleanfax magazine and an industry trainer and consultant, and offers carpet cleaning marketing, disaster restoration marketing and contract cleaning marketing seminars and classes through Totally Booked University, and also IICRC technical training for carpet and furniture cleaning, spot and stain removal and carpet color repair. For more information, visit his technical training website and marketing training website.