Part 2: What factors determine a style of wine?

Published by Tamara Harrison - 26th Aug 2019

Winemaker Adam Barton from Rabbit & Spaghetti established in his previous blog post how important it is to understand the“style” of a wine. Now he’s back to explore those ideas specifically with Shiraz. He wants to provide a better understanding of what factors determine the style of Shiraz. Understanding this will help make connections between the styles you like and the language that might be used to describe them.

This post focuses on vineyards and fruit, the next one will take you into the winery.

At Rabbit & Spaghetti, we make Shiraz from three different regions: the Clare Valley, the Barossa Valley, and McLaren Vale. Generally speaking, the Clare Valley is warm and dry, but its higher altitude and cold nights tend to result in ripe concentrated fruit with excellent acid structure and elegant flavours. The Barossa is also warm and dry, but at a lower altitude, so it produces very full-bodied wines with concentration, big tannins, and great density. And then McLaren Vale has a maritime climate, with warmer nights allowing earlier ripening fruit with opulent flavours, soft tannins, and a rich mouthfeel.

If we zoom in closer to each vineyard, we see that specific site variations influence how fruit develops. For example, exposed sites that receive afternoon sun are warmer and tend to ripen earlier, producing rich/ripe fruit character, while those that are more sheltered tend to ripen later and be less full-bodied, with more spicy/mineral flavours. And if we look at the vines themselves, the many different clones of Shiraz that are planted in Australia all produce wines instantly recognisable as Shiraz but with subtle variations in flavour.

But the way those vines are managed also has a big impact on style. Pruning and crop thinning can be used to manipulate yield, because low-yielding vines produce fruit with more concentrated flavours and tannin, while high-yielding vines may struggle to ripen their fruit, and can lead to green or dilute wines. And because Shiraz fruit likes direct sunlight, trellising systems that expose the fruiting zone (VSP or Scott-Henry trellising) tend to produce riper flavours, while those that leave it shaded (sprawling canopy or ballerina trellising) can promote more spicy/herbal ones.

Choosing when and how to harvest is then crucial to determining Shiraz style. We have to assess the sugar, colour, flavour, tannins in each vineyard, generally aiming to pick at the right time so that we can make wines with ripe fruit characters, balanced acid and tannin, and most importantly flavours that reflect both the variety and the region. Shiraz can be harvested early to achieve lighter, lifted fruit flavours with higher acidity and more red fruits and spice. Shiraz picked too late can result in overripe wines with high alcohol, jammy flavours, and low acid. The aim is to find the right balance depending on what you are trying to achieve as a winemaker.

Then there is vintage variation. Hail early or late in a season can devastate a grower and render a vineyard useless for a season. Heat can be a friend or a foe, as can rain, depending on its intensity and when it arrives. It certainly keeps things interesting – there are never two vintages exactly alike!

So, all of these things ultimately influence the berry and bunch and determine what fruit we have to work with and how we choose to handle it in the winery… and that’s where my next post about Shiraz and style will continue.