On The Up: From rotting to stunning – Hawke’s Bay winery’s sweet dessert wine using fungal disease

Botrytis cinerea or noble rot on Askerne Wine's semillon grapes. Inset: Kathryn and John Loughlin in the tasting room at Askerne Wine's tasting room in Havelock North.

Some say the sweetest juice comes from the ugliest fruit and for one Hawke’s Bay winegrowing family it is more than just a platitude.

Askerne Wines, owned and operated by husband and wife John and Kathryn Loughlin and their family in Havelock North, have been using botrytis cinerea, also known as noble rot, on their semillon grapes since 1999, which they use to produce their range of white dessert wines.

Botrytis is a fungal disease used to create some of the world’s best sweet wines, characterised by their high sugar content, concentrated flavours and often distinct aromas of honey, marmalade, and dried fruits.

This fungus thrives in conditions with high humidity and warm temperatures, particularly during the late autumn months.

It attacks the grape berries, causing them to shrivel and dehydrate. This process concentrates the sugars, acids, and flavours within the remaining berries, leading to a more concentrated and sweet wine.

“The first year was a bit of a nightmare making it,” Kathryn said.

“Getting the pickers to differentiate between what was good and what was a bad rot.”

Semillon grapes come from Bordeaux and are grown a lot in the subregion of Sauternes, that in John’s view has the world’s greatest sweet wines.

“In Sauternes, it’s a valley and at the bottom there’s a river that comes from the mountains,” he said.

“In autumn, the river level’s quite low, the river gets quite warm, and into that from another valley flows another river that’s fed by a spring, and the water is cold.

“When the two waters meet and early in the morning at the right temperature, it gives off mists, and those mists wet the fruit, and they cause botrytis balls on the fruit.”

To get botrytis in Havelock, the Loughlins will in some years spray water on to the vines, but other times it happens naturally.

In France, semillon wine is drunk as an aperitif or pre-dinner drink.

John and Kathryn recommend drinking semillon with strong cheese at the end of a meal, or with a lemon tart.

“When you try the wine, you get a sense of what we’re trying to do,” John said.

“It’s all about balancing sweetness and acidity.”

Jack Riddell is a multimedia journalist with Hawke’s Bay Today and spent the past 15 years working in radio and media in Auckland, London, Berlin, and Napier. He reports on all stories relevant to residents of the region.