Three sticky styles
A large tasting of sweet wines, mostly from New Zealand but also from France and Germany, revealed a wide range of styles. Two obvious extremes were a delicious mature Rieussec Sauternes showing lots of honeyed botrytis character and carrying an alcohol of 14% and a devastatingly pure youthful riesling Auslese by Willi Haag showing intense varietal character and with no botrytis influence plus a modest alcohol of 8%. Both great wines with very different qualities.
In New Zealand, there are three principal premium dessert wines styles, or “stickies” as they are affectionately known.
Like the Willi Haag Auslese, these are simply made by leaving the grapes on the vine for an extended period of ripening without the concentrating assistance of botrytis. In the case of riesling, the flavours of very ripe grapes move from citrus and lime toward ripe peach and apricot. This variety holds its acidity well, a necessary component to balance and residual sugar. Sauvignon blanc is an increasingly popular choice as is pinot gris, although the latter can lack acidity in my view. Chenin blanc is another good, if little used, option.
A good example is the 2016 Mt Difficulty Single Vineyard Long Gully Late Harvest Riesling, Central Otago. It is not excessively sweet and is beautifully balanced with fine, knife-edged acidity. A serious wine offering great value (in a 750 ml bottle. NZD $27 – 95 points).
Freeze concentrated juice or flash frozen berries
Wines made from freeze-concentrated juice are in serious decline, which is a pity because they can offer impressive purity and concentration for a typically modest price. A few producers are picking the grapes before flash-freezing them to freeze much of the water in the berries leaving a sticky residue, which is then fermented.
My favourite example of this style is the 2014 Akarua Alchemy Ice, Central Otago a very sweet blend of gewürztraminer and riesling with a very sweet syrupy texture and concentrated ripe fruit flavours. (NZD $40 for 375ml – 92 points)
Botrytis is vineyard mould that forms on the outside of the grape and feeds on the juice that can penetrate the grape skin without splitting it. If all goes well the berry will shrivel to a raisin-like state with highly concentrated sugars and flavours.
Tokay in Hungary, Sauternes in Bordeaux and the Mosel and Rheingau regions of Germany are able to routinely produce botrytised wines thanks to the vineyards’ close proximity to lakes and rivers. Mist from the water gets into the vineyard sparking off botrytis infection.
Botrytis wines are a little more “hit and miss” in this country although good examples can be made in most vintages. Bunch and sometimes berry selection are often needed to optimise concentration and quality.
Capable of great concentration and sweetness botrytis wines can impress with their power and richness, although I find that varietal character can easily become swamped by the botrytis signature, honey flavours.