He was staying with friends in Newmarket, the world-renowned horse-racing centre and home for more than a century of the traditionally-made sausages, when he met Jane Waddilove, the woman who ran the business - then just a shop in Newmarket High Street with a sausage-making facility above - and learnt that the proprietor was looking to sell.
"It lodged in my mind and one thing led to another," says Mr Ronaldshay, an earl who combines the business with running his family's estate in Yorkshire.
It had nothing to do with his previous business activities - he had run a mail-order company after leaving Arlington Securities, the property company that was taken over by British Aerospace - but he was intrigued by the idea. And five years later, he has contracts to supply Waitrose and Tesco supermarkets.
Still made to the original recipe dating back to the business's beginnings in 1884, Musk Sausages have always been consumed heavily at Newmarket race meetings, with some punters even taking supplies home with them. But Mr Ronaldshay saw a way of building the business into something more substantial, through what he admits sounds like a Blairite policy of "taking sausages to the people".
This resulted in turnover rising 25 per cent last year alone, to pounds 400,000. The company, which still employs only 10 people, is also now making a profit. Getting there has been, he says, simply a case of combining entrepreneurial flair and good quality. But to attract people to buy the product he had to upgrade the conditions in which it was made: having the factory above the shop in a room without air conditioning hardly fitted with supplying Britain's leading supermarkets. So he bought a facility on the edge of the town and put in "EC-friendly things like white walls and showers".
Waitrose came first, and in the past year, Tesco has also started offering the sausages. The deal with Tesco he attributes to the sales efforts of Ryan Human, a long-time employee of Musks who in effect runs the operation in Mr Ronaldshay's absence. Since chipolata sausages are a staple part of the Christmas dinner, the festive season is always busy for those in the trade. But Musks - which now produces three tons of sausages a week - is prepared for this, its first "Tesco Christmas", to be its busiest yet.
Nor can he see any problem in selling a luxury item. Various food scares have encouraged many members of the public to start buying better-quality products throughout the year, but especially at Christmas.
"People do not notice the extra few pence on their shopping bills," he says.