From August to November, from Italy’s mountainous north to its sunniest south, the grape harvest is under way. Once the legal time to harvest has begun – and this date varies by region – winemakers and agronomists try to select the exact moment when their grapes are perfectly mature and ready to be picked. This means keeping one eye, literally, on the grapes themselves and the other on the sky, to be aware of weather conditions. In very simple terms, the longer the grapes stay on the vine, the higher the sugar content and, thereby, the richer the taste. However, if they get wet and stay wet, mould can develop quickly.