This masterclass focused on the variety that’s the darling of the trade but which is sadly not loved so much by consumers: Riesling. It was led by Andrew Hedley of Framingham (left), and Bob Campbell (right), leading Kiwi winewriter. Andrew is arguably New Zealand’s leading proponent of this grape variety, and he explained the sorts of winegrowing decisions that go into producing good examples of this variety.

There are 753 hectares of Riesling in New Zealand, with Marlborough (308 ha) and North Canterbury (285 ha) the key regions.

The ratio of acids in New Zealand are such that pH in the final wine can be very low, even if the total acidity is less extreme, and Andrew reckons that you can taste this. ‘You can feel pH in your mouth,’ he says, and this makes it problematic if you want to make dry Riesling: you want to avoid sweet and sour characters in the wine. So for making dry styles, which he thinks require a lot of attention to detail, dry extract and ripe phenolics are a good starting point. With German and Austrian Riesling, hang time gives a lot of the flavour, and the best wines benefit from dry extract from physiologically ripe grapes. Andrew points out that for vines, the canopy drives ripening and if you have a big canopy it drives ripening fast. So smaller canopies delay the ripening, and result in the balance being on the side of the fruit not the canopy. An alternative route to longer hang time is to load the vine up with more crop but this is risky. Another intervention that can be beneficial is leaf removal in the fruit zone, which helps manage the ripening of the phenolics. The timing of this is important.

In the winery, skin contact can help moderate high acidity. You can achieve a reduction of 1 g/l by 48 h skin contact, but the down side is that the phenolics also go into the juice. Sulfur dioxide use will also alter the extraction of the phenolics and how they are oxidised in the juice. Another winemaking decision is whether or not to clarify the juice. Fermentation with grape solids can be beneficial in developing flavour, but this is a personal preference. It can help develop mouthfeel.

Traditionally in New Zealand Riesling ferments have been inoculated in stainless steel, and this results in pure, fruity wines. But allowing grapes to ferment spontaneously can have a lovely effect on the overall mouthfeel and aroma. There are commercial non-saccharomyces yeast available now for those who want wild ferment character without risk. The use of residual sugar is a key decision, too, and sweetness is achieved by chilling the must as fermentation slows and/or adding SO2.

Then there’s the stabilization process, where interventions are made to get tartrate and protein stability. These can affect wine flavour. ‘In the new world we tend to over-stabilize our wines,’ says Andrew.

Then followed three flights of Riesling.

Dry

Felton Road Dry Riesling 2016 Central Otago, New Zealand
Dry and linear with fresh citrus fruit. Stony and tart with some lime and lemon. Shows delicacy as well as intensity, with no rough edges. Refreshing, primary and juicy, with lots of potential. So lively and intense and nervous. 90/100

Seifried Estate Riesling 2016 Nelson, New Zealand
Very pretty with a bit of grapefruit and also some melony richness. Nice texture to the fruit: this is deliciously open and fruity, with moderate acidity. Such pretty aromatics. 90/100

Black Estate Damsteep Riesling 2015 Waipara, North Canterbury, New Zealand
Nutty, appley edge to the nose, with a hint of honey. There’s ripe apple and citrus fruit on the palate with a deliciously stony, slightly oxidative character. This has substance, and is made in a distinctive style. Lovely texture. 92/100

Spy Valley Envoy Johnson Vineyard Riesling 2014 Marlborough, New Zealand
There’s real breadth and depth to this wine which shows rich, slightly nutty fruit. Ripe citrus and pear here with good depth. Made in a bold, fruit-forward style. Not as lemony as most. 89/100

Off-dry

Maude Mt Maude Vineyard Dry Riesling 2016 Central Otago
Fruity and appealing with a juicy grapefruit and lemon personality. It tastes dry but it’s got some sweetness countering the very high acidity. Juicy finish. Lots of flavour here. 89/100

Terrace Edge Classic Riesling 2016 Waipara, North Canterbury, New Zealand
Lovely texture here with some generosity to the lemony fruit. A bit of honey and some floral perfume, too. Lovely focus and generosity. Tastes dry but there’s some sweetness too. Harmonious. 91/100

Two Rivers of Marlborough Juliet Riesling 2016 Marlborough, New Zealand
This is very fruity and fine with a tangerine and melon richness. There’s lovely citrus fruit driving the flavour, with some sweetness building texture. Long finish: lovely fruit quality here. Off-dry. 91/100

Mahana Riesling 2015 Nelson, New Zealand
Just off-dry with a waxy, nutty edge to the honeyed citrus fruit. Quite lively and bright. Pithy on the finish. 88/100

Fruit Sweet

Pegasus Bay Riesling 2015 Waipara, North Canterbury, New Zealand
Very textural and fruity with bright citrus and pear fruit, and a bit of melony richness. Tastes quite dry even though there’s some sugar. Lovely pure fruit. Linear and with great potential for development. 92/100

Mt Difficulty Target Riesling 2015 Central Otago, New Zealand
Lovely fresh grapefruit with some melon and honey richness. High acidity is nicely countered by the sweetness. Lovely purity here: mouthwatering and juicy with nice weight. A hint of spiciness. Just off-dry, carrying 40 g/l sugar very well. 90/100

Giesen Riesling 2015 Marlborough, New Zealand
This is a large production wine that sells at a great price. So pretty and lively with lovely purity of fruit. Fresh and tangy with lovely purity of fruit. Bright and focused with some tangerine and grapefruit. So pretty. 89/100

Framingham Select Riesling 2016 Marlborough, New Zealand
Honeyed, slightly marmalade-like edge to the lemony fruit. Detailed and pure with a bit of nuttiness and lovely ripe apple richness as well as some spicy notes. Delicious stuff. 91/100