They’re called quintas, Joana tells us, because the rich families who owned the land along this stretch of the Douro river used to let others work it in return for a fifth of the profits. And in this part of northern Portugal, ‘work’ means only one thing: wine. We’re here in the Douro Valley to learn more about it all, including this trip to Quinta do Bomfim, the winery where Dow’s port is made. The valley also produces Cockburn’s — but don’t worry, the Portuguese needed those TV adverts telling them that the Scottish name is pronounced ‘Co-burn’ too. The Americans just dispense with the ‘ck’ — hence James Coburn, who was of Scottish descent.

The biggest vat here holds 84,000 bottles of wine, and the grape-treaders wear tartan shirts in honour of the quinta’s owners, the Symington family (also from Scotland — they’ve been here since 1882). Stay at the Six Senses hotel in harvest season (September and October) and you can join in. Be prepared for a workout: the first hour sees everyone marching in step to release the tannins uniformly, then the next is splash-around party time — including music — to mix them up. ‘I’m amazed the EU health commissars still allow it,’ I say to Joana. She reminds me that fermentation will kill anything unpleasant that our feet leave behind.

Back at Six Senses, local winemaker Francisca provides a tasting lesson, leading us through the herb garden to gather fennel, mint, chive, rosemary, lavender et al, then seeing which of the scents we can detect in various wines. She reacts with amazingly good grace when I say that one of the reds smells like Cadbury’s Fruit and Nut. Yes, she agrees, there are notes of chocolate and berries. A ‘blind’ test (no eyemasks, just black wine glasses) proves that without visual clues you can mistake white wine for red. Even professionals mess up, though probably not the chap Francisca knows who can differentiate between the scents of 50 roses.

The British tend to feel very at home in the Douro valley. The original Mr Cockburn (Robert to his friends) first visited Portugal as a soldier under the Duke of Wellington. After Napoleon had been dealt with, he came back to apply himself to the far more important task of making port. The valley is beautiful — lush green vineyards as far as you can see, the 19th-century quintas looking like tiny white Lego blocks dropped here and there — but unlike the French, the Portuguese don’t get precious about their wine. Their train punctuality used to be British, too: the current Mr Symington’s grandfather was once told that the 16.30 to Porto was two hours late, only to see it leave punctually with no time for him to get on. When he complained he was told that this had been yesterday’s 16.30 to Porto.

Favourite discovery of the trip? It came during a dinner hosted at Six Senses by C. da Silva Wines. They produce some seriously high-end liquids — but are also responsible for Armilar, a ruby port you can find in Lidl for £6.19 a bottle. As your introduction to the Douro, that’s going to take some beating.