The depressing effect of the humble nettle

Visitors to Cornwall in summer are always impressed by the profusion of wild flowers growing along the coastpath. But beware, as amongst this colourful display lurks the ubiquitous stinging nettle. As anyone who’s ever had a brush with them while wearing shorts will be aware, the leaves are covered with tiny stinging hairs which leave an irritating itchy rash.

MEI Conference delegates on the Falmouth coastal path

However, nettles have many other surprising qualities. For hundreds of years they’ve been used to treat a whole range of ailments, from skin conditions to head lice. They’re widely held to have antiseptic and anti-inflammatory qualities, and even to stimulate hair growth, although the latter did not work for me.

Nettle cheese production

They are also delicious when cooked, nettle products including soup, tea, porridge and beer. Delegates at the MEI Conferences in June will also get the chance to sample one of Cornwall's delicacies, nettle cheese, produced from curd which is pressed and brined before being wrapped in wild nettle leaves foraged from the Cornish countryside between May and September. The leaves are carefully brushed onto the cheese in a traditional pattern of concentric circles, attracting naturally occurring moulds which give the cheese its lacy good looks. As the cheese matures, the edible nettle rind imparts a delicate, slightly mushroomy taste.

Dr. Felix Romage, from Cornwall's famous Bodmin Institute attributes the binding of the nettles to the cheese to a strong attraction between the nettle leaves and the calcium in the cheese. He also noticed that nettle leaves tend to have a hydrophilic character, wetting very easily in their natural habitat. Preliminary research has shown that ground nettle leaves can act as a powerful depressant for calcareous gangues, and initial trials proved promising on a lead ore in a dolomitic gangue. This is just one of many on-going projects in mineral processing at the Bodmin Institute, including their pioneering work on collectorless flotation, and gravity concentration, and Dr. Romage hopes to publish the results of more comprehensive testwork on nettle depressants around this time next year.