Spills happen. Unless your carpet is bright yellow, a mustard stain stands out from afar like the glowing sun on the horizon. Instead of searching for ways to hide that bold beacon of a stain, blot it out using several simple spot-treatment methods. Whenever possible, clean up that mustard as soon as you notice the spill to help prevent the condiment from embedding deeper in the carpet. Test any cleaning solutions on an inconspicuous part of the carpet before using them on the stain to ensure the treatments do not discolor the carpeting.
Scoop and Scrape
Whether the mustard spill is fresh or has already dried on the carpet, remove as much of it as possible before attempting to clean the carpet fibers. Scoop up wet mustard with a plastic spoon, working from the outer edges of the spill toward the center to avoid spreading it. Keep a bowl handy to deposit the mustard after each scoop. If the mustard has already dried, scrape it up with the bowl of a plastic spoon or the edge of a plastic gift card. Vacuum up dried mustard debris after scraping to prevent it from spreading and embedding in the carpet.
A Splash of Soda
Club soda acts as a mustard-stain remover suitable for carpeting. Using club soda rather than sweetened soft drinks is crucial; sugary drinks may attract ants and will make the carpet sticky, drawing in dirt. Pour a small amount of club soda directly atop the mustard spot, using just enough to soak the stain without saturating the surrounding carpet. Blot gently with a soft white cloth after a few minutes without scrubbing or rubbing the carpet, as this may spread the stain. Once the mustard color disappears from the carpet, wipe the formerly stained area with a slightly damp white cloth; then blot it dry with a fresh white cloth. A white cloth, rather than one tinted with dye, is useful for blotting all types of spills and stains on carpet. Dye in tinted fabrics may bleed onto the carpeting, causing a new stain.
Simple Soap Treatment
Liquid dish soap helps remove mustard clinging to carpet fibers. Mix a generous squirt of dish soap into a cup of warm water in a spray bottle. Shake or swirl the liquid to ensure it is thoroughly blended; then spray it over the stained area. After five minutes, dab the area with a white cloth moistened with the same soapy solution. As the cloth becomes yellowed, rotate it to a clean area to avoid pressing the mustard back into the carpet. Blot with a fresh damp white cloth to remove soapy residue afterwards; then pat the area with a dry white cloth to absorb excess moisture.
Hydrogen peroxide -- the gentle 3 percent solution sold in drugstores -- sometimes lifts mustard from carpet fibers. Pour a cap full of peroxide over the mustard stain; then mix one part peroxide with three parts liquid dish soap, stirring the solution until it reaches a paste-like consistency. Apply the mixture atop the mustard stain and allow it to soak in for 30 minutes. Blot the area afterwards with a damp white cloth, blotting with a fresh area of the cloth each time the cloth becomes yellowed. Once the stain is gone, rinse the cloth and wipe the area with it again; then blot with a dry white cloth.