“Stickies” is a term commonly used in Australia and New Zealand to refer to dessert wines and on our recent road trip to New Zealand we came across three fabulous examples from Alpha Domus in Hawke’s Bay, Greywacke in Marlborough and Waipara’s Pegasus Bay.
Representing a fraction of New Zealand’s exports (0.02%, or 37,000L in 2014) these wines certainly pack a punch and grab your attention with their luscious texture, array of honeyed and stone fruit flavours and mouthwatering acidity – what’s not to love? 
Notes for the wines tasted can be found below but all three share a common method of production and that is the use of the fungus Botrytis cinerea.
This fungus is a bit of a Jekyll and Hyde character in that if conditions are not perfect Botrytis cinerea will create grey rot rather than the sought after noble rot. Ideal conditions are misty evenings and mornings followed by dry, sunny afternoons, which allow the grapes to dry and manage the development of the fungus, or noble rot, on the grape skins. If conditions are too humid the fungus spreads too quickly causing the grape skin to split and leaving the berry susceptible to damage from other micro-organisms. If grey rot develops the berries will become rotten and often give off a mouldy or vinegar aroma, which will taint any wine made from them.
Botrytis cinerea works by puncturing the grape skin with microscopic filaments, or threads, which create tiny brown spots on the grapes. In a twist of nature, it is these spots that cause the grape skin to be impenetrable to other fungi and bacteria, thus protecting the grape as the botrytis develops. As the fungus takes hold water begins to evaporate and the grapes take on a shriveled appearance.
The different stages of botrytis infection. Source: Great Bordeaux Wines
The colour of the grape will progress from golden to pink, purple and finally a raisin brown colour. There may also be a fine covering of ash-like powder from which the fungus takes part of its name (cinerea).
During the botrytis infection the fungus metabolises some of the grape sugars and acids with the overall effect of concentrating the sugar levels in the juice. A number of chemical reactions also take place, one of which is the formation of glycerol, a compound that contributes to the viscosity of the final wine.
Development of the fungus on the grapes is random and may affect individual berries and bunches differently. For this reason the grapes must be harvested by hand to select the most suitably afflicted berries and to weed out those berries overwhelmed by the fungus and infected with grey rot. The result is high labour costs as not only must this be done by hand but it usually requires several passes through the vineyard as the berries develop at different rates.
Semillon grapes infected with Botrytis cinerea. Source: Wikipedia
Grapes commonly selected for this style of wine are Semillon and Riesling – good candidates for their thin skin and naturally high sugar levels respectively. Semillon is a key component of some of the most famous sweet wines of the world from the Bordeaux and Loire regions in France while Rieslings from Germany are synonymous with sweet wine perfection.
Botrytised wines are the perfect bookends to a meal – they work brilliantly as an aperitif or at the end of the meal when paired with either a cheese board (particularly blue cheese) or a dessert.
While New Zealand might not be the first country you think of for sweet wine it nevertheless has many examples exhibiting the hallmarks of quality stickies that will develop nicely with age. The good news is that all three of the wines below have international distribution so you do not have to be in New Zealand to get your hands on them!
Pegasus Bay, Finale Noble Semillon 2011. Winemaker, Matthew Donaldson.
This wine is a blend of the best six barrels from the 2011 vintage. Conditions in Waipara that year were influenced by the La Niña weather pattern and provided a very mild spring, a warm summer and a long autumn, allowing the grapes to remain on the vine until late June (remembering harvest is usually February – April in New Zealand).
Natural yeasts are used for fermentation before the wine is matured for two years in French oak barriques. After maturation the best casks are selected for the blend.
The wine started with delicious aromas of nuts (walnut, hazelnuts), flowers (honeysuckle, acacia) and citrus peel (tangerine and grapefruit). On the palate there is mouthwatering acidity to off-set flavours of toffee brittle, burnt butter, honeysuckle, dried stone fruit (apricots, peaches), nuts and citrus. Layers of flavour continued to unfold on the very long finish. (Image provided by Pegasus Bay.)
Greywacke, Late Harvest Riesling 2011. Winemaker, Kevin Judd.
The grapes for this late harvest Riesling are sourced from the Ashmore Vineyard in Fairhall to the west of the town of Blenheim. The 18-year-old vineyard is farmed organically and the grapes were harvested in two batches in mid-May. A gentle whole bunch press extracted the juice for fermentation in stainless steel tanks with cultured yeast. The two batches of juice were blended during fermentation, which continued until 120g/l of residual sugar was reached. After fermentation was stopped the wine remained on lees for an additional five months before bottling.
Fresh tropical fruit notes of pineapple opened the wine before leading on to stone fruit (apricot, peach), citrus (lemon, lime) and sweet honeysuckle aromas. This continued on the palate where there was a lovely creaminess to the texture making me think of lemon and lime curd as it coated the mouth, leaving the flavours lingering long after the wine had been swallowed. (Image provided by Greywacke.)
Alpha Domus, Leonarda Late Harvest, Semillon 70%, Sauvignon Blanc 30%, 2014. Winemaker, Kate Galloway.
A combination of partially and fully botrytis infected grapes were used to produce this blend of Semillon and Sauvignon Blanc grapes. Harvest conditions in Hawke’s Bay meant the grapes were able to remain on the vine until May enhancing flavour concentration.
After being harvested by hand the grapes were pressed and fermented in stainless steel tanks for three weeks. French oak barrels were used to mature the wines for six months before bottling.
This wine is slightly lighter in style than the other two with aromas of stone fruit and white flowers. On the palate there were flavours of tangerine, tangy fresh peach skin – that zing you get when you bit into a fresh peach before you get to the ripe flesh. Notes of honeysuckle and very subtle butterscotch came through on the finish. The acidity is high, leaving the mouth refreshed and ready for the next sip. (Image from Alpha Domus.)
1. New Zealand Winegrowers Annual Report 2014.
Robinson, J., ed. (2006). The Oxford Companion to Wine. Great Britain: Oxford University Press