Wine Opinion: whites and oak
Oaked chardonnay, that darling of the late 1980s and early '90s, was shunned by consumers in the mid- and late '90s when lighter wine became the trend. "ABC" (anything but chardonnay) was the phrase among wine lovers, even though they might still claim they loved Chablis (a 100 per cent chardonnay wine from northern Burgundy). Australia, once a major producer of oaked chardonnay, now makes more subtle or even unoaked versions. So why do we still find oaked whites on wine shop shelves?
White grape varieties fall into three broad categories: aromatic, semi-aromatic and neutral. Aromatic grapes are those with pronounced flavours that are derived from the grapes rather than oak or other winemaking techniques. Such flavours are usually specific to the variety. Neutral grapes have mild aromas and varietal characters. Semi-aromatic grapes are somewhere inthe middle, examples being chenin blanc, pinot gris and grüner veltliner.
Aromatic grapes include riesling, with its lime, floral and lanolin aromas; sauvignon blanc, with its distinctive grassiness and gooseberry scents; gewürztraminer with its unmistakable lychee and perfume; the gingery and spicy viognier and the grapey muscat. These varieties don't like new oak because, far from adding complexity, the wood just overwhelms the delicate aromas.
Neutral grapes, as you might have guessed, can be manipulated more easily in the winery. The use of oak is one technique to bring more aromas to the wine. Oak-friendly white grapes include chardonnay, semillon (think Bordeaux white), pinot blanc and the Spanish verdejo.
To understand oak and white wine more deeply we must consider oak fermentation, oak ageing, and whether the oak is new or old.
Chardonnay has a great affinity with oak. But the typical '80s New World chardonnay in a lower price bracket was fermented in temperature-controlled stainless steel tanks at low temperatures to extract the tropical fruit flavour, then aged in new oak, usually American oak chips, giving it a deep yellow hue, rich palate and in-your-face vanilla and toasted aromas. The wine was bold, perhaps pleasing to new consumers but repulsive to experienced ones. I'm glad this style has largely disappeared. Nowadays, 100 per cent oak-aged chardonnay is mostly from California, and the use of oak is less heavy handed, with only three to six months in a mixture of American and French barrels.
Top Burgundy whites, on the other hand, are fermented in barrels rather than stainless steel. The yeast cells act as a barrier between the oak molecules and the wine, resulting in more integrated oak aromas of spices and cloves. The higher fermentation temperature and oak components also create different aromas. The wine is concentrated, full bodied and complex, but subtle. Barrel-fermented wine is also paler, as colour pigments are bound to the yeast cells and drop out as sediment.
Quality conscious producers in the New World are increasingly using Burgundian techniques to make more elegant and restrained whites. Even professional critics confuse top chardonnays from Burgundy, Margaret River, Marlborough and Stellenbosch in blind tastings. Don't believe me? Try the New Zealand Kumeu River Mate's Vineyard Chardonnay (available from Wine'n'things, winenthingshk.com or South African Bouchard Finlayson Crocodile's Lair Chardonnay (bouchardfinalyson.co.za).
Chablis is different again; most producers prefer not to use any oak with their chardonnay to keep from masking the mineral flintiness characteristic of the terroir.
Semillon is another grape that loves oak. The Bordelaise love fermenting and/or ageing their semillon in French oak and blending it with the aromatic sauvignon blanc to make a food-friendly white wine. Oaked semillon is also found in Australia, but wines from Hunter Valley, with high acidity and low alcohol, do not see oak at all.
To complicate things further, some aromatic grapes may be aged in oak, but are usually confined to old oak to avoid added flavour. Fumé blanc is 100 per cent sauvignon blanc from California, aged in oak - a style pioneered by Robert Mondavi to tone down the grassiness - while long-lasting German riesling is often aged in old oak to mellow its acidity.
So don't dismiss white wine with oak. Too much oak will overpower even robust food. But the right amount may spice up the palate.