Visit a winery at most times of the year and not all that much seems to be going on. A winemaker may periodically come to check on a barrel, a bottling line may stutter into life, and, in the larger operations, a lab technician will studiously test samples to the quiet murmur of a radio. But for the most part a winery is a place of museum-like calm.

At this time of the year, however, all that changes for a few weeks. Right now it's vintage season in the northern hemisphere, and wineries are buzzing with activity. An army of itinerant workers, many of them volunteers pick and sort the grapes. As trucks full of grapes arrive from different vineyards, each one needing to be logged, sorted, crushed and sent to a different tank, the bigger wineries will feel a little like a frenetic Saturday night at A&E, with the grapes as patients and the winemaker as the harassed junior doctor allocating staff and resources. At other times, vintage will feel more like a carnival, with wineries laying on alfresco lunch and dinner.

There's an irresistible romance to vintage time that cuts right to the heart of wine's appeal. That date on the label is a reminder that wine is an agricultural product, subject to the whims of the weather that year. It provides a feeling of continual renewal, too, with each vintage effectively being a new product. And it gives wine its magical time-travelling capabilities; that sense, if you drink a very old bottle, that you're drinking the weather and sunshine of one long-gone year.

Am I being too romantic? When I talk to supermarket buyers I'm told that few of us take the year into account when buying a wine, and it's rare for a shop to offer two vintages of the same wine to choose between.

There's also an argument that wines have become much more consistent from year to year, thanks to developments in winemaking and winegrowing. And we drink many more wines from regions (such as Chile and California) where the climate is more reliable, and vintage variation less pronounced, than in northern Europe.

But that doesn't mean the concept of vintage is past its sell-by date. It still matters to producers. It would take a braver soul than me to tell a winemaker who's had their entire crop destroyed, or who struggled with this year's washout summer in northern France and England, that differences between vintages amount to little more than the changing digits on their labels.

And you only have to look at the fuss made around the release of the new vintage in Bordeaux every spring to see that it matters to buyers of so-called fine wine. If anything the importance of vintage for the top wines in Bordeaux (and Burgundy) can be a little overstated, with great wines made in vintages that have had less hype (such as 2008), selling considerably cheaper than wines of lesser quality produced in vintages that have been pronounced as "great" such as 2009 and 2010.

Vintage ratings can only ever be a guide: in good years more producers will tend to come up with the goods, but if a producer is worth their salt, they'll make a decent wine every year. But no matter how skilled a winemaker is at masking the differences, no two vintages of the same wine will ever be exactly alike. With most products, that would be a flaw. With wine, it's part of its magic.

Six value vintages

Martin Códax Caixas Albariño, Rías Baixas, Spain 2011 (£9.99 or £7.99 if you buy two bottles, Majestic) Martin Códax is one of Spain's most consistent producers from vintage to vintage, but from what I've tasted the 2011 vintage in this part of Galicia was a good one lending this subtly peachy white extra vim and zest.

Berrys' Good Ordinary Claret, Bordeaux, France 2009 (£8.75, Berry Bros & Rudd) The 2009 vintage was widely hailed as a classic in Bordeaux, raising the level of quality across the board, as in this excellent fleshy, smooth blackcurrant-and-damson fruited red from the reliable Dourthe operation.

Extra Special Domaine de la Levée Chablis, France 2010 (£9.34, Asda) This is excellent value for a sinuously classy Chablis from a good, if slightly smaller (in terms of crop) than average vintage. It has the steely, mineral blade of all good Chablis, with a bright burst of juicy green apple fruit.

Bodegas Aster One Reserva, Ribera del Duero, Spain 2003 (£11, Oddbins stores) The boiling European summer of 2003 was not all that great for wine, creating many baked, lifeless wines. This is an exception: robust and developing attractive savoury characters alongside sweet coconut and bright cherry fruit.

Yerring Station McIntyre Lane Chardonnay, Yarra Valley, Victoria, Australia 2010 (£12.49, Laithwaites) Cooler climate Australian regions such as the Yarra Valley are as susceptible to vintage variation as Northern Europe, with 2010 being particularly good for this suavely poised, judiciously oaked chardonnay.

Champagne Gimonnet Millésime de Collection Spécial Club, Champagne, France 2002 (£52.90, Armit) Champagne houses only make a vintage-dated wine in years deemed to be special, such as 2002, bottles of which are many producers' current release. It may be expensive, but this example has fabulous complexity, depth and verve.