"The British do something with beer no one else can," said the world-famous brewer to the packed room.
"When excise duty was linked to alcoholic strength in the 1880s, beer strength plummeted. But British brewers developed a knack for getting way more flavour into beers at maybe three-and-a-half, four per cent. British real ale is the only beer in the world that can be so complex and flavourful at such a low strength. No other brewers anywhere have figured out how to do that. That's why British brewers are regarded as the best in the world."
As I sat listening, at a cheese and beer matching event upstairs at the White Hart last week, a few things struck me.
Firstly, while I knew all the above facts, I'd never before connected them in such a simple, elegant way to draw a picture of what makes British brewing so special.
Secondly, I wondered why it had taken Garrett Oliver, an African-American brewer from New York, to point this out to me for the first time. In fact, why is there no British brewer with anything like the profile Garrett has?
And from that, my final point: how many British people — beer drinkers or otherwise — felt the same as Garrett? That our unique beer, envied and applauded around the world, was something to be celebrated?
This then reminded me of another conversation I'd had some months before. At the All-Party Parliamentary Beer Group Christmas reception, I was introduced to Gerry Sutcliffe, then licensing minister. It was just after I'd been named Beer Writer of the Year and on being told this (I didn't tell him, someone else did) he perked up.
"Ah, yes, right, well then," he said, adopting the impression your uncle might use when hunkering down to ask your 10-year-old self how your football team was doing. "So Pete, what can the government do to help our fantastic British brewing industry?"
I got as far as breathing in before he added, "Apart from reversing the beer duty escalator that's helping murder the British pub industry, that's here to stay, obviously."
(OK, I may have put some words in the minister's mouth in the middle of that sentence.)
"Well," I replied, "when you have a government function or diplomatic drinks reception, what drinks do you serve?"
His expression changed. He no longer looked like he was talking to a 10-year-old. He could no longer look me in the eyes.
"Ah," he said.
"Can you imagine going to a French diplomatic function and them serving you, say, Californian wine?" I asked.
"No."
"So what beers do you serve at British diplomatic functions then?"
One of the brilliant skills you acquire as an MP is the ability to signal for someone to rescue you from a conversation without the person you're talking to being able to spot it.
From top to bottom, as a nation we no longer take pride in the stuff we do well. I've seen American tourists walk into pubs, specifically ask for traditional British beer and be offered a choice of Budweiser or Beck's instead. Why? Is it post-colonial guilt? Still? A nationwide, genetic inferiority complex? Cynicism gone mad?
There is one cause I would love to be able to address.
Every time there's a World Cup, we celebrate the gradual reclamation of the St George flag from the racists who once hijacked it. Now we need to go further. We need to be able shout about — or even have quiet pride in — things we do better than anyone else in the world without automatically sounding like a UKIP-voting, 'ethnic'-fearing, Europe-hating Daily Mail/Express reader (no offence).
Can we be proud of what we do without that automatically meaning we denigrate what everyone else does? Most other countries in the world seem to manage it.
That's why I'll be toasting cask ale at the Great British Beer Festival this week, celebrating something no other country has. Just don't ask me to go on stupid hat day. See you there.