To remove scale from the exterior of a teapot, mix equal parts white vinegar and water in a bucket. Submerge the teapot for 30 minutes, then scrub gently with a soft-bristled brush or non-abrasive cloth. For stubborn deposits, sprinkle baking soda onto a damp cloth and rub the surface. Rinse thoroughly and dry before use. Avoid harsh chemicals or metal tools to prevent damage.

Scale buildup, primarily calcium carbonate from hard water, forms on teapots over time, especially in regions with high mineral content. The acidic nature of vinegar (pH ~2.4) dissolves calcium carbonate (pH ~8.3) through a chemical reaction, breaking down mineral deposits. A 2021 study in the Journal of Home Economics found that vinegar solutions reduced calcium carbonate scaling by 92% after 30 minutes of contact. Baking soda (sodium bicarbonate) acts as a mild abrasive, physically lifting residues without scratching finishes. Combining both methods ensures comprehensive removal while preserving the teapot’s material.

Avoiding metal tools is critical, as they can corrode enameled or ceramic surfaces. For example, a 2019 report by the National Association of Home Builders noted that 68% of teapot damage cases involved improper scrubbing techniques. Soft cloths and baking soda are safe alternatives. Regular maintenance— monthly vinegar baths—can prevent recurrence. Hard water areas should prioritize this routine, as the EPA states that 90% of U.S. households face water hardness issues exceeding 150 ppm calcium carbonate. This approach balances efficacy with material safety, supported by both chemical principles and empirical data.