The royal couple were presented with a white rose buttonhole and a posy by a friends Kate Donnelly, five, and four-year-old Jessica Fox, who spent time perfecting their curtseys before their big moment.
The Prince, who became patron of the show in 1998, and the Duchess were give a warm welcome as they toured the exhibitors, spoke to producers and enjoyed sampling some of the regional food on offer in the food hall.
Judy Bell, chief steward at the Cheese and Dairy Show, said: “It was brilliant. They are a really lovely couple who are very relaxed and easy-going.
“Prince Charles is so passionate about cheese and he knows what he likes. He wanted to see the softer cheeses but got caught up chatting to all the makers. I loved that they came to support us.”
The couple also visited the Ampleforth Abbey stand, where the Prince tasted some of the famous cider made by monks at the Yorkshire monastery.
Father Terence Richardson, prior of the monastery, said: “He tried a good swig and said he found it very good and he enjoyed it. It was a great privilege meeting him.”
As they made their way out of the food hall, The Prince of Wales bought two packets of pork scratchings from Rose Cottage Pantry, based in Driffield, and sampled game pie at Voakes Pies stand.
Charles, who is patron of the Yorkshire Agricultural Society which organises the event, and Camilla chatted with the public and were applauded on several occasions during their whistle-stop tour.
Pupils Ellie, Katey and Keeley, aged 10, from Gillshill Primary School, Hull, said: “Prince Charles asked us when the school holidays were and if we were skiving off school!” to see some of the rare goat breeds.
Their Royal Highnesses then reunited and Prince Charles presented outgoing show director Bill Cowling with a commemorative stick.
Mr Cowling, who is retiring after 10 years at the helm, said: “It has been a wonderful day and a wonderful honour for the show. Hundreds of people have spoken to them and shaken their hands.”