Ditching premox - Bob's Blog

The Oxford Companion to Wine (OCW) explains that, “a white wine which has oxidized naturally over a long period is likely to be deep yellow in colour, perhaps browning, with aromas of cooked fruit, sometimes quince, eventually dank, dead fruit, possibly sherrified and acetic. Typically these negative effects will be immediately apparent on opening and pouring”.

“A prematurely oxidized white wine will also show some advance in the colour, more in the dull yellow range, and this may happen after the bottle has been open for a minute or two. The first danger sign in terms of aroma is bruised apples or furniture polish, which can strengthen considerably with aeration. Aromas of stewed fruit and prunes are common in prematurely oxidized red wines.”

The two causes of premox were quickly identified as poor corks and low sulfur levels. The mid-90s were the halcyon days for cork manufacturers. With few alternatives available, demand for cork was at an all-time high. Many winemakers believe that cork quality suffered as a result. At the same time, climate change was producing riper, softer and more accessible white Burgundies and many producers were using lower sulfur levels so that their wines could be enjoyed earlier.

Kumeu River Winemaker and Master of Wine Michael Brajkovich believes cork is the major culprit for premox. Corks are variable, which helps explain the varying levels of oxidation that many white Burgundy drinkers have experienced in a single case. He is dismissive about the theory that premox can be traced back to vineyard management. “I am sure that the type of press used, the soil management, and even the degree of effeuillage will all have an effect on the susceptibility of white wines to oxidise, but if they were so significant, then surely all of the wines in that dozen would have been similarly affected.”

The simple solution to Burgundy’s problem would be to switch to screw caps. When I made the suggestion to a Burgundy winemaker he agreed that it would solve their premox woes, but added that screw caps would not be accepted by their customers. An increasing number of white Burgundy makers are embracing Diam closures. “It has been most encouraging to see the likes of William Fevre, Leflaive, Lafon and Jadot recently embracing the Diam closure,” says Michael. “Whenever we have seen these, the results have been consistently good because there is no oxidation. The only downside has been a wood dust character from some of the early Diams, but with the newer examples, particularly with Diam 30, this is negligible.”

According to Bruno de Saizieu, Director of Commercial Marketing and Vice President Sales and Marketing for Diam, 60 percent of Grand Cru White Burgundy is now sealed with Diam, while 45 percent of all Burgundy uses Diam. Thankfully premox may, at least in Burgundy, soon be a thing of the past.