The importance of fruit set
There are many things throughout the year that can affect grape vines and how a vintage will turn out. When it comes to establishing a crop in the vineyard the two most important parts are flowering and fruit set. If the vines don’t have enough water then they will not flower properly which means there won’t be enough potential fruit on the vines. Once the flowers are out they need to be pollinated to create the berries that will eventually turn into wine.
Besides access to water, temperature is a big factor in how well grape vines flower and set their fruit. This is where McLaren Vale, Barossa, Clare and many other regions had problems this year. With higher temperatures the flowers on grape vines close and depending on how long that lasts, may not pollinate and become grapes. This is exactly what happened this year.
Varieties will go through their normal growing processes at different times which means some varieties this year were ok but most had “poor fruit set”. Cabernet Sauvignon, Tempranillo and Vermentino in particular were bad this year while Grenache goes through its processes later and luckily had cooler temperatures during fruit set and therefore more berries turned into grapes.
The photos below show the difference between a Shiraz and Grenache bunch of vines. As you can see the Shiraz bunch is a lot smaller and the individual berries are small, large and some haven’t pollinated like the green one. Whereas the Grenache bunch is big, plump and almost all the berries are around the same size.
One of the reasons people get excited about good wine vintages is all the things that have to go right to create such great wines. Fruit set is just one of the many steps it takes to create those wonderful glasses of joy.
Now go enjoy a glass!!