There are numerous debates on whether it is safe to drink from a copper cup. Some support drinking from it, citing health benefits, while others express concerns regarding copper leaching. 

Recent research on the subject has heightened this confusion as Montana researchers discovered that unsafe levels of copper can leach into the Moscow Mule cocktail (a drink traditionally served in a copper mug). This popular cocktail has been served in a frosty copper mug for years as the copper metal is said to enhance the drink’s aroma and effervescence once it oxidises. But the new research asserts that flavour is not the only thing the copper cup imparts.

In less than 30 minutes, the copper leaches into this drink made of ginger beer, lime juice, and vodka to levels higher than the recommended 1.3 parts per million of copper that the Environmental Protection Agency sets as a safe level for drinking water.

So what’s the deal? Are copper cups safe to drink from— or not?

This article will explain the difference between a lined and unlined copper cup, how to tell if your cup is made of pure copper, and how to safely store and drink from a copper cup.

What Is a Copper Cup? Lined vs Unlined Copper for Drinks

The first step to guarantee your safety when drinking from a copper cup is to understand the different types of copper cups:

1. Unlined (Solid) Copper Cups: Classic copper cups made from copper. They have a warm reddish-brown glow and carry substantial weight in your hand. They also develop natural patina—a greenish or blue hue that signals authenticity.
2. Lined Copper Cups: The lined copper cups are lined with stainless steel or tin on the inside to create a barrier between the drink and copper. Ideal for acidic drinks such as the Moscow Mule, as they minimise the risk of copper leaching. The interior of these cups is usually silvery or grey.
3. Copper-Plated Cups: Typically have a base metal such as steel or aluminium, which is then coated with a thin layer of copper. They are not as heavy or as durable as real copper.

Next, let’s explore how to safely drink from the various copper cups.

How to Safely Store and Drink Water in a Copper Mug

Regulatory Guidance on Copper Leaching

Is it safe to drink from a copper cup? Well, that depends on your ability to comply with the recognised safety standards. 

In the United States, the Food and Drug Administration (FDA) offers guidance on what foods and drinks should and should not come into contact with copper. The FDA advises against using copper cups for acidic drinks such as citrus juices, vinegar, wine, or cocktails like the Moscow Mule. Acidic drinks heighten copper dissolution, increasing the risk of consuming unsafe levels of copper. 

On the other hand, the Environmental Protection Agency (EPA) and the World Health Organization(WHO) asserts it is safe to consume water and other non-acidic drinks from a copper cup as long as it is within the recommended safety level of 1.3 mg copper ions per litre of water.

So, do not use unlined copper mugs to drink low pH (acidic drinks), and hot liquids.

Care Routine for Cleaning, Polishing, and Storage

Here are simple, practical tips to keep your copper cup clean and safe to drink from:

1. Wash and dry your copper cup after every use.
   
   
2. Do not leave drinks in the copper cup for long hours and empty the cup before refilling. 
   
   
3. Polish your cup using lemon & salt, vinegar and salt, or baking soda paste to remove any tarnish.
   
   
4. Store mugs in a dry, well-ventilated area or use a desiccant packet to absorb moisture in humid environments.
   
   
5. Inspect lined mugs for lining scratches. In case of scratches, do not drink acidic drinks using the cup.
   
   
6. Do not use abrasive material and harsh chemicals to clean copper cups.

 Bottom Line

From antimicrobial properties to healthier skin, there are numerous health benefits of drinking from a copper cup. However, before drinking from a copper cup, ensure you follow the necessary safety precautions to avoid ingesting excessive amounts of copper ions. If you want the full benefits, always choose pure copper cups from Purely Copper, made from 100% copper, as mixed or coated materials may reduce effectiveness and safety.