Hiro Kusuda was born in Japan, studied winemaking in Germany and has settled in New Zealand where he makes wines that reward those who cellar them…

They say good things come to those who wait and we all know how long fermentation can take, so it’s lucky that winemakers are a patient bunch. Or should I say, they have no choice when it comes to watching their grapes transform into wine and the wine change as it ages.

A conversation with Martinborough winemaker Hiro Kusuda this month threw a controversial variable into the concept of cellaring wine, namely: corks versus screw caps.

Which closure allows wine to put its best foot forward as it ages?

Kusuda is the founder of the eponymous Kusuda Wines in Martinborough in the Wairarapa, a region with a big name for Pinot Noir but relatively minuscule production. The area’s entire production is only about 2% of New Zealand’s annual wine output because spring winds often wipe out a significant proportion of potential crops by reducing the sizes of grapes and bunches.

This hasn’t stopped Martinborough wine producers like Kusuda from forging something of a cult following for his wines. He makes three: Pinot Noir, Syrah and Riesling. All up, his production each year is about 1000 cases, sometimes less, if the wind has a big say in matters. Most of the wine sells to Japan, with the balance trickling  onto shelves in the United Kingdom, Australia and New Zealand, including at his local store, Martinborough Wine Merchants, which was formerly The Martinborough Wine Centre.

Kusuda prefers the taste of aged wines sealed with corks rather than screwcaps. It’s an unusual perspective in New Zealand these days. According to New Zealand Winegrowers, approximately 97% of this country’s wines are sealed with screw caps. The majority of the remaining 3% is sparkling wine.

Kusuda uses corks and screwcaps on all of his wines, dividing the choice of closure between different wine markets and his own cellar, but choosing to seal 100% of his Rieslings  with screw caps.

His choice of closure is part pragmatic, part personal. He wants to see which closure allows wine to fare best in good cellar conditions in the long term.

“Wines mature differently under different closures. I taste wines under cork and screw caps often and about eight or nine times out of 10, I prefer cork.”

He concedes that wine under cork can taste less fresh when aged than the wine under screw caps.

“But if you’re opening a 10 year old Riesling, would you look for fresh fruit? You have certain expectations for wine of a certain age, and I think that the balance between freshness and fruit profile and tertiary flavours can vary.”

While Kusuda confesses to a personal preference for the types of flavours in old wines that are sealed with corks, he remains committed to all of his Rieslings being sealed with screw caps, as mentioned above. This takes into account the market in the Southern Hemisphere, which is strongly focussed on screw cap closures. It is also perhaps an inadvertent acknowledgement on his part that there are unpredictable rates of cork taint, random oxidation (under cork) and accentuated sulphides, which can be more pronounced in certain wines sealed with screwcaps, but can equally be problematic in wines that are sealed with effective corks, which can also accentuate the aromatic perception of sulphides.

Despite all of the closure issues, debates and pragmatics, which will remain hot topics within the wine community, Kusuda makes wines that can transform beautifully with time in a cellar. His Riesling is arguably the best example.

A wine to keep

 2015 Kusuda Martinborough Riesling $49, 12.5% ABV

Hiro Kusuda made his first Martinborough Riesling in 2009 and he seals all of his Rieslings with screw caps. The wine contains 2.9 grams of residual sugar per litre, which makes it drier than many mainstream whites but its pronounced citrus and peach flavours combined with balanced high acidity give it strong fruity appeal and  refreshing flavours, which make it taste intensely zesty. Just 3760 bottles were produced.