Never. The interior of every SAMA Homes copper glass and tumbler is 100% raw, unlined, and unlacquered 99.6% pure virgin copper so your drinking water maintains direct ionic contact with bare copper. Only the exterior surface has a light food-safe polish to help preserve the outer shine.

Natural interior darkening (patina) is definitive chemical proof that your glass is 100% raw, unlined pure copper! Pure copper contains zero iron and cannot rust. When bare copper meets water and oxygen, it naturally forms copper oxide spots. To restore the bright pink-gold copper shine in 60 seconds, rub the inside with half a lemon dipped in 1 tablespoon of salt, rinse thoroughly with warm water, and dry immediately with a soft cloth.

No — use exclusively for plain room-temperature or chilled water (and non-acidic chilled beverages). Because single-wall 99.6% pure copper conducts heat instantly, pouring boiling tea or coffee inside will make the rim and walls too hot to touch. Furthermore, acidic drinks (lemon water, citrus juices, vinegar, wine, soda) react rapidly with raw unlined copper and cause excessive copper leaching and a metallic taste.

Pure copper tumblers and mugs are single-wall metal vessels with ultra-high thermal conductivity. When filled with cold or iced water in a warm room, natural condensation ("sweating") forms on the exterior—which is why copper mugs feel so frosty in your hand! Simply place a coaster beneath your glass on wooden tables.

No — strictly hand wash only. High heat and harsh dishwasher detergent tablets permanently strip the exterior polish and heavily oxidize raw copper, voiding warranty coverage. Wash gently by hand with mild soap and warm water, and dry immediately.

Orders operate on a strict 12-hour cancellation window and dispatch within 24–48 business hours from Chestermere, Alberta, Canada. Orders over $75 CAD qualify for Free Tracked Priority Shipping across Canada and the United States ($15 CAD flat rate under $75 CAD; international orders outside Canada ship Delivered Duty Unpaid / DDU). Unused, unwashed, factory-sealed items in original packaging may be returned within 30 days of delivery (subject to a 10% restocking fee; shipping is non-refundable). Strict Hygiene Final-Sale Rule: Any glass, tumbler, or mug that has been unsealed, rinsed, washed, or used is 100% Final Sale. Any courier transit damage must be reported within 24 hours of delivery with photos of the outer box, shipping label, and item.