It was a royal mission too far. The Prince of Wales has tried his hand at making strawberry tarts during a visit to a family bakery.

He donned a white coat and hat to tour Reid's in Thurso, Caithness, where workers watched him fill pastry cases with cream using a piping bag.

Reid's has been producing shortbread, biscuits and oatcakes since 1966, many of them based on 100-year-old recipes passed down through generations.

Charles topped the cream with a strawberry and laughed as he attempted to pipe over some strawberry glaze which oozed out of the top end of the piping bag.

"I've no idea how these things work," he told bakery worker Lauren MacKenzie, who performed a demonstration for him.

The 19-year-old, from Thurso, said: "He did very well. He didn't grasp the bag tight enough at the top, but I think he did really well."

The Prince, known as the Duke of Rothesay in Scotland, toured the premises on the Ormlie industrial estate, where huge vats of flour, shortening and butter stood ready to be transformed into cakes, biscuits and confectionery.

Charles saw ingredients sieved and weighed, and watched as machines pumped out biscuits on to trays to be packaged.

Charlene Banks, 18, showed him the early stages of the production of "banoffee oaties".

The accountancy and finance student at Edinburgh's Heriot Watt University, also from Thurso, is working over the summer at the bakery where she started helping out aged 14.

"He asked what type of flour I was using and how the scales worked. He seemed really interested," Ms Banks said.

Charles was also given a meringue piping demonstration by Scott Newman, 25, but did not try the technique himself.

Local worker Mr Newman, who has been with the bakery for 10 years, said: "He asked me if it was difficult to do and I told him 'It's years of practice'."

Donald Reid, 72, began the bakery with the help of his mother Mary Ann Reid and with recipes provided by his grandmother Margaret Ann Reid.

Now his sons Graeme and Gary help run the company which exports many of its products abroad.

Mr Reid senior said: "When I was a wee boy I would work in the kitchen with my grandmother and turn out things, scones and the like. That's where the beginnings of this were."

The firm's biggest-selling product is its all-butter shortbread, presented to the prince in a hamper along with toffee cake, maple and pecan oat biscuits and other treats.

Charles later visited a meadow near Dunnet Bay, a two-mile beach on the northern coastline, which is home to rare plants and the most northerly population of bumblebees and blue butterflies.

Wearing a kilt made from Hunting Stewart Modern tartan, he met Hamish Pottinger, owner of the Greenland Coronation meadow, and Ken Butler, author of a book about plant life in Caithness.

On a walk over the land Mr Butler pointed out plants such as the Scottish primrose, Baltic rush and the fragrant orchid which is said to be a favourite of Charles.

Mr Butler, 74, from Thurso, said: "He always enjoys looking at plants and wildlife and it was a pleasure to welcome him. His interest has sparked a number of initiatives here in Caithness."

The visits continue a series of engagements in the north of Scotland which has a long association with the Royal Family.

At the weekend Charles oversaw the Mey Games in his role as chieftain of the event.

Lord Lieutenant of Caithness, Anne Dunnett, said: "We are very glad he comes. He does so much for Caithness."