Walnut – the royal nut

Usually used as a snack or garnish, the walnut was known as the ‘royal nut’ back around the year 1000.

The two common species of walnuts grown today are the English walnut and the black walnut. The English walnut originated in Persia while the black walnut is native to North America. Being difficult to hull, the black walnut isn’t generally cultivated in orchards, but there are many cultivars of the English walnut which are the ones you see in store.

Around 4.5 million tonnes of walnuts are grown around the world each year.

As food, they can be eaten raw, toasted, or pickled. They’re also used in muesli, and can be used to make soups, pies, and cakes, and are great sprinkled on ice cream.

It’s the main ingredient in baklava, the popular dessert variously ascribed to Persia, Turkey, and Greece. It was a favourite of the character Corporal Max Klinger in the TV series MASH. You can find a recipe here.

Outside of food, walnuts are said to be good for heart health, a claim that has qualified support from the US Food and Drug Administration. It also features often in folk medicine.

Other uses have included inks and dyes. Walnut ink is thought to have been used by both Leonardo da Vinci and Rembrandt. The husks were also used to make a brown fabric dye in ancient Rome that was also used in medieval Europe for dyeing hair.

While those uses are gone, ground walnut shells are used today for abrasive blasting to clean vehicle and other metallic parts. The ground shells are an alternative to glass beads and they’re less abrasive than sand. They’re also less toxic than sand blasting which can emit silicon oxide.