CAREFULLY, I lifted the bottle from the box and placed it on the table between us. We both looked at it, then at each other, then back at the bottle.

I’d never been simultaneously so nervous and excited about opening a beer, but then this was no ordinary beer. It was something different; something special. Something very, very old.

What we were about to drink was a bottle of York Brewery Jubilee Real Ale 1977, a rare relic from a home brewing business that once stood at number 4 Bishopthorpe Road (no relation to the modern-day York Brewery). It was a Jubilee beer alright, on Jubilee weekend – but for an altogether different Jubilee.

I had picked it up on eBay, having been inspired by my namesake and fellow beer-lover Gav Frost, who recently found and drank a 1929 beer.

We had left it to settle in a dark corner of the cellar of the Old Bell Tavern in Harrogate for a few weeks, then retrieved it last Friday, prepared ourselves with a modern-day pint from the bar, and went for it.

I wiped some of the dust from the neck, placed the bottle in a slops bucket just in case it exploded upon opening, and tentatively approached with the opener.

“Naturally conditioned,” read the label. “Decant from yeast sediment” – although we were still none the wiser about what to expect. There were no tasting notes to suggest what the beer should have tasted like 35 years ago, let alone how it might have matured.

I removed the cap and the beer was as flat as tap-water. No bubbles; no fizz; no need for the bucket.

“I don’t need it to taste great,” I said. “I just hope it’s drinkable.”

Frosty picked up the bottle, wary of the inch-thick yeast sediment at the bottom, and slowly began to pour a dark, dark brown liquid.

We smelt it; and it smelt like sherry. “Like an Amontillado,” said Frosty, who knows more about such things.

“Think back to what beer was like back then,” he added. “This was the early days of Camra – many beers were so bad, people must have wanted to brew at home instead.”

We clinked our glasses, toasted the 70s, and drank. Frosty winced at its very earthy character but I was pleasantly surprised.

“If you offered that to someone at random, I’m not sure they would say it was a beer,” I suggested. “But it’s not bad.”

“No, it’s not – but the taste doesn’t match the smell,” he countered.

We went on, smelling it, swirling it, tasting it, scrutinising it, holding it up to the light, debating it and discussing it. But – tellingly – we continued to drink it, gradually warming to it as we did so.

And then we spotted our chance: a regular in the Bell, an enthusiastic dabbler in all things beer, but someone who had no idea what we were doing.

“Drink that Todd, and tell us what it is,” Frosty commanded, having swiftly hidden the evidence. Here was the moment of truth, a blind taste-test.

“It has a nice smoky flavour,”offered Todd. “It’s malty, and sweet.” We nodded smugly.

Might it be a Brewdog Paradox, he wondered. Or a Mikkeller? We shook our heads. “It tastes like raisins, tobacco, and leather,” he went on, clearly trying to solve the riddle.

We felt compelled to put him out of his misery and when we did, he felt impressed and vindicated. “It’s like in Pete Brown’s book, when he has a bottle of really old beer, and says it reminds him of a tannery,” he concluded.

Our beer was nowhere near as old as that one, but it was a fair age nonetheless. When it was made, 35 years ago, Thatcher wasn’t yet PM, Liverpool had just won the first of their European Cups; the Sex Pistols were topping the charts; and some of us were still five years away from being born.

It’s a beer that should scarcely have lived to see the 1980s, let alone the second decade of the 21st century. But survive it did. Until Friday.

Andrew Bates, the manager at the Old Bell, felt it tasted like a Belgian cherry beer; I ended up feeling it was like a whisky-beer; Frosty thought it was like a sherry; and Todd – who went in blind – probably summed it up better than the rest of us.

Before we moved back to the 2012 bar, we poured out the dregs and eyed the glass queasily. It looked like a coal-miner’s bath-water, and when we held the bottle up to the light, the insides looked to be caked in mud. Half an hour later, that thick lacing remained. I couldn’t help but wonder whether our own insides had been similarly decorated. But if so, it was a price worth paying for one of the most inimitable beers I'll ever drink.