As thousands of cheeses battled it out at the Nantwich International Cheese Awards recently, Diana Pilkington landed the dream role of being on the judging panel.

It’s the hottest day of the year but I am mercifully cool under a big white tent in a field in Cheshire.

The chill in the air isn’t for my benefit, however, but for the blocks of cheese stretching out in meticulous rows all around me.

From the industrial-size slabs of Red Leicester to perfectly smooth wheels of Gouda, the Nantwich International Cheese Awards is a dairy lover’s paradise.

Nearly 4,000 entries from 27 countries are battling it out to win the coveted title of Supreme Champion at the biggest event in the industry’s calendar.

As one of 156 white-coated judges, I have a small part to play in deciding their fate. But I’m not quite prepared for how demanding it will be.

I’m sampling the hard-pressed speciality cheeses that have been produced outside the UK. It’s a category that runs the gamut from Gruyere to Comte and Cheddar with blueberries, which makes them tricky to compare.

“If you’re doing a Stilton class, for example, where all the cheese is the same type, it’s always easier,” agrees Tim Fisher, who is head cheese maker at Butlers Farmhouse Cheeses, based near Preston in Lancashire, and one of the two other judges in my team.

“We’re looking for a cheese that’s technically good and what you’d expect from that type,” he says.

“But at the end of the day, cheese tasting and grading is very much about personal choice. If there’s a flavour you really don’t like, it’s difficult to put that completely to one side.”

To sample the wares, we plunge a cheese iron (a bit like an apple corer) inside each plastic-wrapped block, twist it and pull out a cylindrical section of cheese. A nicely full iron will earn higher marks.

We then snap off a piece each, rub it between our fingers to feel the texture, taste it and mark it out of five before carefully re-plugging the hole in the block.

Some types are an instant turn-off – the Cheddars with seaweed, red wine and Irish Porter are all too wacky for my taste – but halfway through sampling 53 cheeses I am seriously full, and struggling to distinguish one Gruyere from the next.

We plough on regardless and, after selecting our favourites, taste them again to pick our top five. The gold in our class goes to a scrumptious 24-month-old Parmigiano Reggiano.

“It’s not too salty – for me it’s a perfectly balanced cheese,” declares our fellow judge Gert Van Den Hoven, an industry expert from Holland.