The Prince of Wales officially opened the new extension of an organic yoghurt factory – nearly 20 years after he first visited to open an earlier expansion.

Charles toured Rachel's Organic in Llanbadarn Fawr, near Aberystwyth, as part of the first day of his Welsh summer tour.

He met Rachel Rowlands who founded Britain's first organic dairy in 1982 and though she sold the company in 1999, she still remains involved in its running.

Charles, who appeared to be in good spirits, laughed, joked and chatted with staff at the business, which employs more than 100 people and met Nigel Truman who remembered his first visit in 1998.

Mr Truman said: "When we had the first extension, he came and opened it so I told him I was here last time.

"He said that was a long time and he remembered it well.

"He asked about our work and where we are going on a summer holiday. We told him Balmoral."

Charles also had a chance to taste Rachel's Greek-style yoghurt with honey, one of a range of flavours made at the site which expects to produce 17,500 tonnes of yogurt this year.

"He loved the yoghurt, he said it was really creamy," said Rachel Brittain who served him.

"He wants to try the rice pudding and wanted to see if it is better than his cook makes."

Ms Brittain spoke to colleagues and made sure some of the rice pudding was in a hamper presented to Charles before he left by nine-year-old twins Rachel and Tomas James.

Unveiling a plaque to mark the occasion, Charles said: "Having successfully brought the whole system to a grinding halt I suspect, for which I can only apologise, I just wanted to say what a great pleasure it is to come back to this site and discover one person who was working here 21 years ago who could remember.

"In that time an awful lot has changed and from what I can gather it is now the most remarkable bit of plumbing I have ever seen.

"I do hope that it will make an enormous difference not only in terms of sales but also in terms of the dairy sector in Wales which is of such great importance."

Ms Rowlands said the success of the company was down to its dedicated employees.

She said: "To see what's happening today makes me so proud of what they have achieved.

"It is not my work any longer. What started 35 years ago on a farm, I never dreamed of this."

She said the investment in the business would bring huge benefits for Ceredigion and demonstrated the sustainability of the brand.

The Prince also officially opened Volac’s Biomass plant at the company’s Felinfach site near Lampeter.

The biomass plant produces 20 megawatts of energy which is sufficient to power the equivalent of 20,000 homes. The plant uses wood as a fuel which is sourced from sustainably managed forests within a 55 mile radius of the site.

The wood comes to the site in various forms; either round wood (which is chipped on site), saw mill residue (from local saw mills) and a small amount of brash (tree trimmings from the harvesting of trees).

Energy produced at the site is exported to the adjacent Volac dairy plant which consumes 100% of the biomass plant output.

James Neville, Volac CEO, said: “Our major investment of £38 million in the plant enables Volac to generate sustainable energy to meet the growing needs of our business at Felinfach. It has enabled us to reduce carbon emissions from our Felinfach operations and reduce the carbon footprint of our products. Through this investment we have been able to employ an additional five staff from the local community.”