The Prince of Wales and Duchess of Cornwall meet with students from the restaurant, 'Jamie Oliver's Fifteen Cornwall', on Watergate Bay beach near Newquay.
The Duchess of Cornwall has called on English wine producers to come up with an alternative name for sparkling wine to rival champagne.
Her Royal Highness's comments came as she toured one of Britain's leading vineyards - and sampled a glass of their fizz.
Only wine produced in the Champagne region of France can use the name but the Duchess described how sparkling wine made in the UK was "very good".
To mark her trip to the Camel Valley Vineyard near Bodmin in Cornwall, the Duchess, who celebrates her 67th birthday tomorrow, was presented with a huge bottle of sparkling rose wine - containing nine bottles.
The vineyard was started by Bob and Annie Lindo 25 years ago when they converted their farmland to growing vines and, with their son Sam, have gone on to great success.
Their wines have won international awards and a sparkling variety was used in the toasts at a Commonwealth leaders summit in Sri Lanka last autumn hosted by The Prince of Wales.
At a reception featuring local dignitaries and loyal customers like Jill Stein, who runs restaurants and other outlets with her former husband celebrity chef Rick Stein, The Duchess cut a cake to mark Camel Valley's 25th anniversary.
With a glass of sparkling wine from 2011 called Annie's Anniversary in her hand, The Duchess said: "I think we should come up with an idea for British sparkling wine because it's champagne and very good champagne - it should have a special name."
Due to the restrictions on using the name champagne, Camel Valley vineyard call their sparkling wine Cornwall - after the county it is made in.
The Duchess's father Major Bruce Shand was a wine merchant and passed on his love for whites, reds and rose to his daughter.
The Duchess of Cornwall meets Ben and Scarlett from Padstow school, during a visit.
When hosting receptions for the press on official foreign tours she is often seen with a large glass of red wine in hand while chatting to journalists and photographers.
Her Royal Highness, who is President of the United Kingdom Vineyards Association, also told the guests that the Camel Valley sparkling wine drunk by heads of government at the Commonwealth summit "slipped down a treat".
Each year the vineyard produces 100,000 bottles of wine of all types from grapes grown on south-facing slopes in an idyllic part of north Cornwall.
Sam Lindo shook The Duchess's hand when she first arrived and then rushed off to London where one of his sparkling wines has been shortlisted for an award due to be presented tonight.
Before leaving, Mr Lindo, who has been named Wine Maker of the Year three times and saw the vineyard's sparkling rose crowned World Champion in 2010 and 2011, described the conditions in Camel Valley which help to create his business's popular wine.
He said: "I think it's a very cool climate. Grapes grow slowly and seem to take on the characteristics of fruits like gooseberries and strawberries and they stay on the vine much longer than anywhere else in the world and have an acidity that lifts the wine.
"To have The Duchess here is amazing - really, really brilliant."
Earlier, The Prince admitted that his surfing days were behind him when he visited the surfing mecca of Watergate Bay, near Newquay, with Camilla.
The Prince recalled the days when he was a regular sight on boards at nearby resorts such as Constantine and Polzeath on the county's north coast.
His Royal Highness told the beach's RNLI lifeboat manager Steve Instance: "I'm past my sell-by date for surfing."
On the beach he met the Surfing Chefs - a group of students from Cornwall College Camborne, near Redruth, who are on a placement at Jamie Oliver's Fifteen Cornwall restaurant immediately above the cove.
One of them, Carla Viladonmat, 25, said The Prince had told her he was envious of them.
She said: "He said that he had done it himself quite a few years ago and wished he could get back out there now."
The Prince and The Duchess also spent time chatting with a group called Surf Action, who teach the sport to military veterans, many suffering post-traumatic stress disorder, to help them to adjust to life after war service.
Rich Emerson, one of the charity's founders and a former Lance Corporal in the Queen's Royal Irish Hussars, said it had helped him come to terms with life after serving in the first Gulf War.
He said: "It's something to do with the salt water. You get a lot of positive vibrations in the salt water. We mainly deal with a lot of post-traumatic stress."
His group also trains chefs from Fifteen as a team bonding exercise.
Their Royal Highnesses met formerly unemployed apprentice chefs at the restaurant, which is run by the TV chef Jamie Oliver and managed by the charity Cornwall Food Foundation.
It trains the apprentices on an intensive 16-month course designed to use the magic of food to unlock their potential and create the chefs of the future.