A soy sauce stain can happen anywhere, whether you are at home or out at a restaurant. Most experts agree that it's preferable to treat a soy sauce stain when it's fresh; if allowed to oxidize, the stain will typically be more difficult to remove. The best stain removal method will probably depend on the type of material affected, as well as the cleaners you have on hand. You can try to treat the stain yourself with cold water and ammonia or a mild detergent, or bring the item to a professional cleaner.
Soy sauce ingredients include soybeans, water, salt, and sometimes wheat, depending on whether it's a brewed version. It sometimes contains preservatives, as well as artificial colors and flavors. Most soy sauces are brown to black in color, making the stains somewhat difficult to remove. It might be slightly easier to treat a stain caused by a light soy sauce.
The most common tip for removing most stains is to treat them right away. It might not be possible to remove a soy sauce stain that has set in or that has been there for a long time. Experts usually suggest that, if the stain does not come out of an item after the first wash, you should avoid drying it until after the stain has been removed and the garment has been washed again.
Fabric, upholstery and carpet are the three most common types of material stained by soy sauce. On fabric, including clothing, you could try using water followed by ammonia and then laundering it as usual. Upholstery often requires hand washing using a sponge or cloth and mild dish soap with cool or cold water. You can use warm water and dish washing detergent on carpets, and blot the stain, rather than scrubbing it. In most cases, you should use something stronger like ammonia only if the soap and water don't work.
When attempting to treat a soy sauce stain at home, keep in mind that some products can be harmful when used together. For instance, ammonia and bleach should not be mixed, as they will emit toxic fumes. Furthermore, many professionals recommend using "green" cleaners, such as natural laundry detergents or vinegar, for example. You could also use a liquid enzyme stain remover or a soaking solution of sodium borate and water to treat a soy sauce stain.
If the stain is difficult to treat, or you are simply unable to remove it at home, then you may want to bring the stained item to a professional cleaner. A dry cleaner might be able to effectively remove the stain using stronger chemicals. To prevent permanent soy sauce stains in the first place, you could purchase a product that you carry with you and use on the go, such as a stain removal pen. Available at many stores, they are convenient when you are unable to treat a stain at home right away.