Cold start yields late harvest

HEATHCOTE winemakers are playing a waiting game after a chilly start to the growing season.

Vineyards would typically be filled with grape pickers by mid-to-late-February, but this year everything is on hold until the fruit ripens.

Silver Spoon Estate winemakers Peter and Tracie Young said they expected to start harvesting in mid-March.

“Grape vines go through a period of dormancy and that dormancy is governed by temperature,” Mr Young said.

“The main factor that knocks them out of dormancy and into budburst is soil temperature, and from then until when you harvest is pretty much a standard time.

“There’s an average of two degrees temperature difference between the north and the south of the Heathcote wine region.

“So, you’ll find that the first bud burst and the first harvest will be up north in Corop and it will then come down through the region.

“It’s like the cherry blossoms in Japan, here it’s a wave that comes down from north to south.”

Mr Young stressed that individual grower practices also affected harvest times.

“We don’t irrigate our vines and therefore the soil gets warmer more quickly,” he said. “We’re not putting water into the soil which is cooling it down.

“But generally speaking, buds burst is round about the second week in September.

“The berries then start going from green to red in the first week in January, but this year it’s only just happening now.

“At the moment the berries are quite warm and hard, when they get ripe they get doughy and springy and you can push them down and they come back quite hard.

“That’s one of the things we look for, we monitor the sugar levels but the other thing we look for is that springiness.”

Mr Young said sugar levels in the grapes rose as they ripened which was an important factor in wine making.

“To produce a wine of about 14 per cent alcohol we need 250 grams of sugar per litre in the berry, so that’s a cup of sugar for every litre of juice that the vine produces,” he said.

Silver Spoon Estate grows several different varieties of grape including tempranillo and grenache.

“Temprano is Spanish for early, so tempranillo means little early one,” Mr Young said. “We have little tempranillo and big fat grenache.

“Tempranillo ripens faster than grenache, it’s an early ripening versus a late ripening.

“There would be at least four weeks between the harvest for a tempranillo and a grenache.”