To remove scale from a teapot, fill it with equal parts white vinegar and hot water, let it sit for 30 minutes, then scrub with a soft brush. Rinse thoroughly and repeat if necessary. Alternatively, use lemon juice or baking soda paste for milder scale. Always rinse the teapot after use to prevent mineral buildup.

Scale forms when hard water containing calcium and magnesium ions reacts with heat, leaving deposits on surfaces. A 2021 study by the Environmental Protection Agency (EPA) found that 85% of U.S. households use water with hardness levels exceeding 150 ppm, leading to scale accumulation in tea brewing equipment. Vinegar (acetic acid) dissolves calcium carbonate scale through a chemical reaction:

CaCO₃ + CH₃COOH → Ca(CH₃COO)₂ + CO₂ + H₂O.

This reaction is 90% effective on scale within 30 minutes, as shown in a 2019 Journal of Home Economics trial. Lemon juice (citric acid) works similarly but is gentler, ideal for delicate teapots. Baking soda paste neutralizes acidic scale but requires longer contact time. Commercial descalers often contain phosphates, which the EPA advises against long-term use due to environmental concerns. Regular descaling every 2-3 months maintains teapot efficiency, reducing energy consumption by 15% in electric kettles (National Appliance Association, 2020). Consistent maintenance preserves the teapot’s material integrity and ensures optimal heat transfer for brewing.