Start of veraison in Shiraz

As I write this, our Shiraz grapes have started veraison.

In viticulture, veraison is the onset of the ripening of the grapes.

The official definition of veraison is “change of colour of the grape berries”. Veraison represents the transition from berry growth to berry ripening, and many changes in berry development occur at veraison. Some of these changes include the grape berries start to soften and size increases due to cell enlargement. The sugar content of the berry increases rapidly, acidity decreases, and the pH increases.

Also, the vines alter their focus from energy creation (through photosynthesis) to energy consumption where it concentrates its energy into ripening the grapes.

At this time the water requirements for the grape vines are higher, so a higher rate of irrigation is required to ensure a smooth transition. This week we had just had over 50mm of rain falling on the vineyard. It was a lovely all day event that wet the soil really well. We couldn’t have asked for better timing!

We await what the rest of the season brings, but so far it has been a good season with a mild Spring, good regular rainfall. Drying out in Summer, as would be expected, but not too many excessively hot days or nights. Of course nothing in farming is a certainty, and we try not to get too far ahead of ourselves in what could be.

Cheers,
John