What if your nebuchadnezzar (20 bottles) is corked? And you won't get a balthazar (16) into a wine rack or the fridge.The most appropriate package is the magnum. It's festive, it's substantial and it looks mighty impressive. It's also supposed to be the ideal medium for ageing wine. The received wisdom is that a magnum keeps wine better than a standard bottle because relatively less oxygen gets into the wine. Is this a myth? When Jacques Seysses of Domaine Dujac in Burgundy noticed a difference between the same wine aged in different-sized bottles, he decided to bottle some of his 1978 Clos St Denis in halves, bottles and magnums.

But when he brought in a group of experts to taste them blind almost 20 years on, they couldn't tell the difference. Seysses' theory is that "during transportation, the small volume of air between wine and cork creates more oxidation in a bottle than a magnum, and only then is the ageing process affected". Bollinger keeps all its older wines in magnums, because, according to managing director, Ghislain de Montgolfier, "the best balance between air and wine is a magnum". Before blending with the latest vintage for consistency, this "reserve wine" is deliberately kept lightly sparkling because the carbon dioxide gas, which creates the bubbles, acts as a preservative. Bollinger is the only champagne house to do this and one of the few not to sell champagne in magnums. Looking at what's on the shelf, the millennium magnum is something of a hit-and-miss affair.

I was disappointed, for instance, with the two white burgundy magnums on offer at Waitrose: one a dull bourgogne from Boisset, the other a mediocre example of chablis from the normally reliable Chablisienne co-op. Why pay £15.99, when for a penny less, you can have two bottles of the 1998 St Véran Domaine de Curis from Louis Jadot? To make up for it, the 1991 Cosme Palacio Tinto Rioja (£19.95, Waitrose; Oddbins Fine Wine have the 1989, £24.99, and 1992, £19.99) is not just a splendid-looking creature in its own right, but deliciously smooth with a mature liquorice and aniseed spice bouquet and a rich, velvety texture and smoky maturity. More youthful but also intriguing is a nice, rustic red burgundy from the Cÿte d'Or, a 1997 Gevrey Chambertin (£29.99, Tesco). Penfolds have made two special magnum bottlings, both of which offer oodles of fruit flavours. First, the blackberryish 1997 Penfolds Koonunga Hill Shiraz/Cabernet (£12.99, Safeway, Majestic, Wine Cellar, Oddbins - coming soon), and second, the spicy, rich 1998 Penfolds Bin 2 Shiraz/Mourvÿdre (£13.99, Tesco). Magnums of fizz make great gifts.