Storming the castle: behind the scenes at Chateau Margaux

When you're already king of the castle, you may look down from your lofty heights with satisfaction to the gratifyingly dirty rascals below. However, you also need to watch those rascals carefully, lest they steal a march on you and end up storming your castle walls while you are busy looking in the other direction.

As with nursery rhyme castles and rascals, so with winemakers. Experimentation and willingness to change must be the lifeblood of any wine-making operation, but when you're a premier grand cru classé, a castle if ever there was one, the stakes can be very high. You cannot stand still and risk letting others catch up with you; equally you cannot leap into the unknown and risk damaging the reputation of a Chateau that has been built up over centuries. Additionally, the need to judge results over a long period is especially important when the resulting wine may well be aged for many years before consumption.

This is the dilemma facing many top class wine producers the world over and I gained an insight into some of the areas that Château Margaux in particular is working on at a tasting in London this February, hosted by Paul Pontallier, director and winemaker at the Château for the past 30 years.

Conventional, organic and biodynamic

We tasted a number of themed flights, tasted blind, starting with wines made from grapes farmed by different methods: conventional, organic and finally biodynamic agriculture. The wines were all Cabernet Sauvignon from the 2010 vintage.

Paul Pontallier was keen to point out that their current methods, though conventional, are pretty close to organic. Of the three, I found the biodynamic sample the most expressive, with depth, perfume and fine, ripe tannins. My second favourite sample turned out to be the conventional method one, which had more assertive, though still ripe, tannins. The finish, though, was elegant and long-lasting and perhaps a better guide to the future evolution of the wine. The organic sample was my least preferred, with unwelcome green and woody notes.

These are my personal preferences on the day and they did not chime with Paul Pontallier's own opinion – whose least favourite wine was the one made by conventional methods. Though he stressed that this is just a snapshot of a long-running experiment and, frustratingly, they have had many different results along the way, with little consistency.

To de-stem or not de-stem?

The next flight highlighted the influence of stems in the ferment for red wines. Traditionally Château Margaux practises almost 100% de-stemming, but they wanted to compare this with 1% of whole stems and 1% of stems cut into pieces.

Here the results were much more clear cut, with the 100% de-stemmed sample showing greater harmony and balance than either of the other two. The sample containing chopped stems was the least successful, being both less expressive and more astringent.

These 2009 Cabernet Sauvignons seemed to confirm that the Château is already following the best method – though it is important not to generalise from specific research and to recognize that Merlot might produce different results.

Is cork still best?

The onward march of the screwcap as the preferred closure for more, and better quality wines, has been hard to miss and it would be a surprise to find any quality-conscious producer who was not experimenting with it. Paul Pontallier showed us the same wine, a red blend from 2003, sealed with an airtight scewcap, a permeable screwcap and a natural cork.

Incidentally they have also experimented with synthetic corks, but the results were so catastrophic that they called a halt to the experiment.

On the day I, along with most people in the room, preferred the wine sealed with an impermeable screwcap. Second and third favourites were less clear cut, but I found the cork the least successful – though there was some bottle variation and other tasters preferred the cork. This same tasting had been conducted a month previously and the impermeable screwcap had again triumphed, with the cork second and permeable screwcap third.

The mixed results highlight the complexity of this issue – and the need for it to run for many more years before any firm conclusions can be drawn.

When we repeated this process with a white wine, Pavillon Blanc 2004, the overall favourite in the room was for the wine secured with a natural cork. Personally I felt the permeable screwcap was more successful, but I must confess that I found this a hard style of wine to evaluate: the oak is so dominant that it was hard to discern any varietal fruit character – and this for a wine that is 100% Sauvignon Blanc!

This tasting was a tantalizing glimpse into the workings of a top flight producer and how they face up to the challenge of deciding which innovations are worthwhile taking up – and which are ultimately going to be a flash in the pan and offer no long term benefits.