{"title":"Cups","description":"\u003cp\u003eThe tumbler is the oldest form of tamra jal: no lid, no thread, just fill it, leave it and drink it. Three hundred millilitres, about a glass of water. Where that habit comes from is in \u003ca href=\"\/blogs\/kennisbank\/tamra-jal-de-ayurvedische-traditie-van-water-drinken-uit-koper\"\u003etamra jal\u003c\/a\u003e.\u003c\/p\u003e\u003csection class=\"kopero-composition-update-20261021\"\u003e\u003ch2\u003eNew composition analysis - 21 October 2026\u003c\/h2\u003e\u003cp\u003eRTC (2021): 99.21% copper and 0.75% zinc. URS (21 October 2026), a separate bottle sample: 99.18% copper and 0.498% zinc.\u003c\/p\u003e\u003cp\u003eThe new report concerns one copper bottle. It cites ASTM E 478:2008 as its reference method. It is a composition analysis, not a migration or food-contact test. No batch number is recorded.\u003c\/p\u003e\u003cp\u003e\u003ca href=\"\/pages\/test-dossier#meting-2026\"\u003eRead the test dossier\u003c\/a\u003e\u003c\/p\u003e\u003c\/section\u003e\n\u003cp\u003eSolid copper at 99.21% (RTC 2021) purity, independently tested against the European food-safety standards, with no coating and no inner lining. You choose between a smooth and a hand-hammered version; what that difference means day to day is in \u003ca href=\"\/blogs\/kennisbank\/glad-of-gehamerd-koper\"\u003esmooth or hammered\u003c\/a\u003e. Looking for a copper cup with a handle, for coffee or tea? Then have a look at the \u003ca href=\"\/collections\/mokken\"\u003ecopper mug\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eSet the tumbler out in the evening on your bedside table or the kitchen counter and drink it in the morning. How the ritual fits an ordinary week is in \u003ca href=\"\/blogs\/kennisbank\/tamra-jal-in-de-praktijk\"\u003etamra jal in practice\u003c\/a\u003e, and how often a day is usual in this tradition in \u003ca href=\"\/blogs\/kennisbank\/hoe-vaak-per-dag-zou-je-uit-een-koperen-fles-moeten-drinken\"\u003ehow often a day\u003c\/a\u003e. If the tumbler tarnishes over time, lemon and salt (not too hard: salt is mildly abrasive and dissolves well in the lemon juice) bring the shine back.\u003c\/p\u003e","products":[{"product_id":"kopero-premium-koperen-beker","title":"Kopero Copper Cup","description":"\u003cp\u003eThe cup is the original form of tamra jal. Before there were bottles with screw caps, a copper cup of water simply stood beside the bed in the evening and was drunk in the morning. Three hundred millilitres is exactly what you finish in a swallow or two.\u003c\/p\u003e\n\u003cp\u003eThat also makes this the simplest way to try the ritual. Fill, leave, drink, rinse and let it dry upside down. Where the habit comes from is set out in \u003ca href=\"\/blogs\/knowledge-base\/tamra-jal-the-ayurvedic-tradition-of-drinking-water-from-copper\"\u003ethe article on tamra jal\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eThe cup comes \u003ca href=\"\/blogs\/knowledge-base\/smooth-or-hammered-copper\"\u003esmooth and hammered\u003c\/a\u003e. Smooth keeps the surface even and quiet; hammered is worked by hand and carries its own pattern that breaks the light. The copper underneath is the same either way. The cup is formed from a single piece of copper, with no seam and no solder.\u003c\/p\u003e\n\u003cp\u003eThere is another reason copper became the tradition. In EPA tests, cleaned copper killed more than 99.9% of bacteria such as MRSA and E. coli within two hours, and since 2008 it has been registered in the United States as an antimicrobial material. It is also a trace element your own body uses, from energy metabolism to the transport of iron in your blood. Stainless steel and plastic are inert and do neither. The evidence is in \u003ca href=\"\/blogs\/knowledge-base\/can-copper-really-kill-bacteria-the-evidence-from-epa-to-southampton\"\u003ecan copper really kill bacteria\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eHow to get the most out of your copper\u003c\/h3\u003e\n\u003cp\u003eFill the cup with still water. Carbonated water, lemon water and other acidic drinks dissolve copper faster and belong in glass. Do not leave water standing in it for more than a day either; the ritual is one night, not one week. On how much per day, see \u003ca href=\"\/blogs\/knowledge-base\/how-many-times-a-day-should-you-drink-from-a-copper-bottle\"\u003ethis article\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eHand wash, no dishwasher. Warm water and a soft cloth are enough; lemon and salt (not too hard: salt is mildly abrasive and dissolves well in the lemon juice) polish the shine back. The full routine is in \u003ca href=\"\/blogs\/knowledge-base\/maintaining-a-copper-bottle-cleaning-polishing-and-storage\"\u003ethe care article\u003c\/a\u003e.\u003c\/p\u003e\n\u003cp\u003eDiscolouration is part of it. Pure copper without a coating grows darker the more you use it, and it can always be polished back. \u003ca href=\"\/blogs\/knowledge-base\/why-is-my-copper-turning-green-or-black-and-is-that-a-problem\"\u003eWhy is my copper turning green or black\u003c\/a\u003e explains what you do and do not need to do.\u003c\/p\u003e","brand":"Kopero","offers":[{"title":"Smooth","offer_id":54697656516949,"sku":"8720726791496","price":29.95,"currency_code":"EUR","in_stock":true},{"title":"Hammered","offer_id":54697656549717,"sku":"8720726791502","price":29.95,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1071\/7259\/4005\/files\/kopero-beker-glad-1.jpg?v=1791102152"}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1071\/7259\/4005\/collections\/kopero-combi-bekers.jpg?v=1788937455","url":"https:\/\/kopero.com\/collections\/cups.oembed","provider":"Kopero","version":"1.0","type":"link"}