It takes awhile for Porto’s styles to sink in: ruby, tawny, late-bottled, colheito, crusted, vintage. (Who’s ever heard of crusted port?) The fix is easy, though: Visit more wineries, taste more Port, absorb more information, and gradually assemble the jigsaw.

The most useful tidbit is offered by our host at Vasconcellos, one of the few boutique producers amid the giants in Vila Nova da Gaia. “Port is like whiskey,” he says. “There are single malts and blended whiskeys. With Port, there are single vintages and blends.”

Eureka! It’s true. Normally with tawnies and rubies, you’re talking about blends. But each category has its exceptions. With tawnies, the single-vintages are called colheita. With rubies, the single vintages are called (duh) vintage, port. But if it’s an off year, or if a vintage-quality wine is left to age in barrels beyond vintage’s three-year limit, it becomes a late bottled vintage, or LBV. Savvy Port shoppers know LBV offers the best price/quality ratio of all. (Think Brunello declassified to Rosso di Montalcino and sold at Rosso prices.)

Every style has its partisans. “I hate vintage Port,” our young host declares provocatively. “My favorite is the 30 Year Old tawny; it shows a nutty, layered character, but still has the pudding.” Hmm. We try it: a cola-colored tawny, with some caramel notes and a nutty, almost sherry-like character wrapped around a sweet Port core (ah yes, the “pudding”). Very tasty indeed. I’m sold – euphemistically speaking. The 78 euro price tag keeps us from a real sale.

We also hit Calem, where we particularly enjoy watching their orientation video while sitting inside a huge oak cask. Previously at lunch, we’d had a very nice red table wine from Calem (Curva 2007 Douro Vihno Tinto). Only 13 euros at one of the finest restaurants in town. These dry reds from the Douro Valley -- now with their own Douro DOC category – can be stupendously good and stupendously priced. Plus, the DOC has the prettiest logo I’ve ever seen (above).

Tomorrow we head upstream and will be driving alongside the hills pictured on that logo. The Douro Valley is a UNESCO World Heritage site and one of the most breathtaking landscapes in the wine world. I can’t wait.