HALFWAY through my first pint of Nightwatchman — a lightly roasted, malty ale from the East London Brewing Company — the bartender replaced the low-volume Little Willie Littlefield LP with the atmospheric vinyl crackle of “Lightnin’ Strikes” by Lightnin’ Hopkins. I opened a packet of bacony pork scratchings, or cracklings, and took in the afternoon palette of a classic British pub: a low wooden counter with 10 hand-pulled taps of local ales unknown to me, backed up by eight farmhouse ciders that I’d never heard of. Around the dim, denlike space, neighbors read the papers or chatted quietly over their glasses in the way I imagined Londoners must have done for centuries, and I found it very easy to slip into conversation with the avuncular gentleman next to me.

What was difficult to grasp, however, was what he told me: that this beautiful pub, the Southampton Arms, in the north London neighborhood of Gospel Oak, hadn’t actually been part of London’s great drinking culture since before the beginning of time. In fact, the rarefied atmosphere (and beer list) we were enjoying dated from late 2009, part of an explosion of great beer, and great places to drink it, in the British capital over the past few years.

“I suspect it is the most exciting time to be drinking beer in London since the early ’70s,” said Des de Moor, author of “The CAMRA Guide to London’s Best Beer, Pubs & Bars,” when I met him over a quiet pint the next day.

Indeed, London is experiencing a craft beer renaissance so remarkable that keeping up has become a full-time job for connoisseurs like Mr. de Moor, who regularly charts the new developments on his Web site. Despite its history as the home of many of the world’s best-loved brewing styles — IPA, porter, stout, brown ale and Russian imperial stout are all from here — London’s beer culture suffered through several decades of decline, resulting in just seven working breweries by 2006, according to Mr. de Moor.