Don’t get tardy. Quickly blot away the excess and rinse in cool water from the back.
Rub any residual stain gently with liquid laundry detergent that includes enzymes prior to laundering.
Inspect the item. If any stain remains, repeat the steps above prior to tumble drying the item.
Wash quickly as the turmeric in mustard is a yellow dye that could become permanent.
Remove excess mustard.
Rinse with water. You mustard being more careful!