Soak in citric acid for food-safe rust removal

Dissolve 1/3 to 1/2 cup citric acid powder per gallon of hot water. Submerge the rusty item and soak for 2-4 hours for moderate rust, or overnight for heavy buildup. Scrub off residue, rinse thoroughly, dry, and oil.

Why It Works

Citric acid chelates iron oxide, pulling it away from the base metal. Hot water dramatically speeds the reaction. Being food-grade, it is safe for cast iron cookware, kitchen knives, and food-contact tools.

Tips

• Hot water is essential — cold solutions may take days to achieve what hot water does in hours
• Available in the canning section of grocery stores or in bulk online for $5-8 per pound
• Less aggressive than vinegar, so there's less risk of etching if you slightly over-soak
• The solution turns yellow-orange as rust dissolves — it can be reused until exhausted
• Rinse thoroughly — residual acid can discolor some metals