One of the trendiest drinks of 2017 is the Moscow Mule: a refreshing mix of vodka, ginger beer and lime juice.
Much of the cocktail’s appeal is down to the fact it’s often served in very Instagram-friendly copper-coloured mugs.
But now a US state department has issued a warning that these pretty vessels could give you food poisoning if they have not been specially made for cocktails.
The stark message comes from the state of Iowa’s Alcoholic Beverages Division, which has warned that copper and copper alloys are poisonous if consumed.
When these metals come into contact with food or drink with a pH level lower than 6, copper may leak into the edible substance and can be accidentally consumed.
The warning states: ‘High concentrations of copper are poisonous and have caused foodborne illness.’
The pH level of a Moscow Mule is well below 6, which is why Iowa and several other states have issued the warning as these cocktails are often served in copper mugs.

Symptoms of copper food poisoning can occur immediately which includes nausea, vomiting (green), diarrhea and can leave a metallic taste in the mouth.
Never a good idea to dispense high acid foods with anything copper but that drink sounds good.