Gravy stain

In detail

Gravy is one of the few household stains that is genuinely three problems at once: rendered fat, dissolved protein from the meat, and starch or flour used to thicken it. Each responds to something different, and two of the treatments actively work against the others. Heat and hot water set the protein fraction irreversibly, so the instinct to attack a greasy mark with the hottest water available is precisely wrong here. The carpet institute's entry puts the sequence in an order that surprises most people: nail polish remover, then solvent, then a detergent solution, then a vinegar solution, warm water and ammonia. Solvent leads because the fat is what is binding the deposit to the fibre; once it is gone, the water-soluble protein and starch fractions are reachable. On fabric the equivalent sequence is a cool pre-soak to deal with the protein before any heat, then a detergent with a lipase in it for the fat. An old gravy mark that has yellowed has usually oxidised its fat fraction, and that is a different and much harder problem than the original stain.

Why

• Gravy stain is explained by Protein denaturation
• Gravy stain is explained by Solubility and polarity
• Gravy stain is explained by Heat-set stains
• Gravy stain is explained by Why oil resists water