Vintage 2017 has just commenced in the Hunter Valley and between now and April our various wine regions will follow.

The harvesting of wine grapes (vintage) is the most important step in the process of winemaking and the busiest time of year in the wineries.  The time of harvest is determined primarily by the ripeness of the grape as measured by sugar, acid and tannin levels with winemakers basing their decision to pick based on the style of wine they are producing. The weather can also shape the timetable of harvesting with the threat of heat, rain, hail, and frost which can damage the grapes and bring about various vine diseases.  

Different grape varieties respond to different conditions in their own way. On the whole, for instance, Shiraz responds particularly well to dry, sunny conditions that favour the ripening of its sugars, that’s why growers in the Barossa Valley have been particularly successful in producing wines made from this grape. In Tasmania however, the cool climate resulting from its southerly latitudes and surrounding ocean is highly beneficial to grapes such as Pinot Noir which flourish over a longer ripening period.

Grapes are therefore harvested at different times and, across Australia, Vintage 2017 will vary in timing across the different regions. In the Hunter Valley, the harvest usually lasts about six weeks beginning with white varieties including Semillon, Verdelho and Chardonnay in mid-January, before ending in February with the reds. In the cooler climate regions however vintage will start later, often as late as April in Tasmania.  Most regions will start with their white grapes and conclude with their reds.

The first of the Chardonnay grapes are transferred to the winery at
Audrey Wilkinson in the Hunter Valley

Depending on the grape, the region and the kind of wine that a winemaker wishes to produce, the following steps in the harvesting process will vary in time, technique and technology. But for the most part, every wine harvest includes these basic steps:

1. Grapes are picked
   Grapes are picked from the vines either by hand or using machinery
2. Grapes are crushed
   Often grapes are transferred to a sorting table to remove any unevenly ripe, under ripe, or disease damaged clusters before a destemmer removes the stems and crushes the grapes.  White grapes are then transferred to a press to remove the skins before fermentation, red grapes are transferred to the fermentation tanks skin on, which is what gives red wine its colour
3. Fermentation
   Fermentation is the process in which the sugar converts into alcohol. This stage includes adding yeast to the tanks so that fermentation can take place.  The process of fermenting red wine is more labour intensive as the carbon dioxide released during the process causes the grape skins to rise to the surface. Winemakers must punch down or pump over the “cap” several times a day to keep the skins in contact with the juice.  After fermentation red wine grapes are pressed to remove the skins and then transferred to age in barrels.
4. Ageing
   The flavour of a final wine is greatly impacted by the choice of ageing vessel and the duration of ageing. Winemakers can choose from stainless steel vs oak, new oak vs aged oak, french oak vs amerian oak etc.  Ageing can take anything from a few months to several years.
5. Bottling
   When a winemaker feels a wine has reached its full expression in ageing, the wine is bottled for consumption.