Spring may be when the vineyard bursts from dormancy back to life, but Summer is when things begin to get exciting, giving us a glimpse towards the potential of the next vintage.
Summer is the season that can make or break vintage. The climate on Kangaroo Island in early summer can still be variable. Optimum conditions for a good vintage are warm, dry days with mild winds. Excessive rain, wine or humidity can all spell disaster.
As flowering begins to end, the fertilised flowers start to develop a seed and grape berry to protect the seed. This stage is critical as it determines the potential crop yield.
Now is the time we begin to get a good idea of bunch development and quality on the vine with an insight into how vintage may shape up if the weather remains at optimum conditions.
At this stage of the growing season when we pray for warm sunny days, moderate frost-free nights, gentle breezes and little or no rain.
During January, the tiny bunches of grapes go through a rapid period of growth. Once they reach around half their final size, they enter the stage of véraison, usually around 40 – 50 days after fruit set. However, the grapes remain hard, have very little sugar & are high in organic acids.
Throughout véraison the berries begin to ripen, turning from green and begin to turn purple, red and golden. This tipping point is when the vine begins to turn its energy away from vine growth concentrating on developing sweetness in the grapes.If necessary, leaf thinning is undertaken to allow the grapes more access to light & increase airflow to minimise disease risk.
After véraison the grapes swell & fill with water. During this ripening period, sugar levels rise & acid levels drop. Colour pigments, flavour compounds & tannins develop. Watering stops to induce mild water stress, inhibit shoot growth & encourage concentrated character in the ripening grapes.
A close eye is kept on the vineyard & when flocks of marauding birds arrive, nets are installed across the vineyard to protect the crop. Once nets are on, vintage is only a matter of weeks away.
Many regions begin vintage in February, however in the cooler conditions on Kangaroo Island, wine vintage traditionally begins a few weeks after other South Australian regions, often in March.