Although today is officially “National White Wine Day”… I’m still in the mood for a red. Especially given the wild weather of late.
Here at Somerled, it’s actually “National Oh-no! The 2018 Shiraz is almost sold out (but don’t worry the 2020 is ready to go) and will soon be heading to the museum day!”
And I had a heap of information about Shiraz that I couldn’t squeeze into last week’s post, so should we continue?
In particular, I’d like to talk about…
HOW SHIRAZ IS GROWN IN AUSTRALIA
Shiraz is a vigorous vine and can yield large quantities of grapes on a single vine. Even in low-fertile soils (typically higher-quality wines come from lower-yielding vines).
The Shiraz vine is relatively adaptable. It can be a prolific grower in the right climate, but is sensitive to poor fruit setting. Shiraz is mid-to-late budding and ripening, picked mid-harvest.
Attention must be given to rootstock because it’s sensitive to chlorosis (parts of the foliage turn yellow due to lack of chlorophyll). If left on the vine too long, Shiraz has a tendency to lose aroma and acidity quickly. The resulting wine can taste jammy.
Shiraz grape bunches need to be protected from excessive heat and sunlight. These conditions increase the likelihood of water loss and berry shrivel. When this happens, the grapes ripen too quickly. The resulting wines can develop a cloying jamminess with a flabby mouthfeel.
Shiraz vineyards on shallow soils require irrigation. However, many old vineyards, or those on deeper soils, are dry-grown. The vines access water from sources deep below the surface.
Shiraz vines, especially hardy dry-grown vines and those with age, can cope well in adverse conditions. As a result, they produce grapes with rich fruit concentration and intensity. If Shiraz is irrigated too generously, it can become too vigorous and produce wines that lack flavour concentration.
One of the main purposes of pruning is to ‘tell’ the vine how many bunches of grapes to grow. This is achieved by diverting energy growth to the right place.
Given Shiraz is a vigorous vine, pruning is especially important to control excessive growth. Shiraz pruning can be done by hand or mechanically, typically during the winter months or closer to spring.
The yield of Shiraz vines is dependent on several factors, including:
- Age of vine: The yield of old Shiraz vines tends to be lower, but the grapes are very concentrated in flavour and intensity.
- Vine vigour: If vineyard growth is especially abundant and the yield is allowed to rise, Shiraz’s distinctive savoury
qualities can diminish.
- Site characteristics: Including soil type, aspect, light sources and climate.
Harvest timing and maturity of fruit are both informed by the wine’s intended style and climate.
To ripen fully, Shiraz demands a good ripening season. In those conditions, it is picked mid-harvest.
In cooler climates, Shiraz often requires a longer growing season to ripen completely. As the grapes ripen, the sugar content increases and the acid content decreases. The key to an ideal harvest is to find the point when the sugar-acid balance is just right.
Left to ripen more deeply, Shiraz’s peppery qualities develop into notes of stewed plums and dark cherry.
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And lastly, let’s have a quick look at some winemaking techniques…
WINEMAKING: TECHNIQUES INFLUENCING SHIRAZ STYLE
Varying techniques may be used, allowing the winemaker to create their own wine style and to build character and complexity.
Whole-bunch (aka cluster) fermentation
Stems are left in contact with the grapes, which leads to a higher tannin content and heightened aromatics. It can also boost the wine’s ageing potential.
Stems are added to a ferment that began with de-stemmed fruit.
Fermentation begins with whole, unbroken grape clusters still on the stems. In an anaerobic environment, like a vat filled with carbon dioxide, the grapes will begin to ferment within themselves (using their own enzymes). This works until the alcohol reaches about 2%. Carbonic maceration imparts a unique character and leads to fruit-forward styles.
Lactic acid bacteria, occurring naturally or added to the fermented Shiraz juice, triggers the conversion of harder malic acid into soft, smooth lactic acid. Winemakers can also choose to employ partial malolactic fermentation. This decreases acid in the wine, stabilises wine and shapes aroma and flavour.
Wild or indigenous yeasts that are naturally present in the microflora of the grape are used to ferment the wine rather than adding cultured yeasts. There aren’t always textural differences present after wild yeast fermentation, but it can lead to a more complex wine.
Co-fermentation with Viognier
When Shiraz is co-fermented with a very small amount of Viognier, the wine’s colour is brightened, the perfume is heightened and the palate becomes more supple.
Involves extraction of the fermenting juice (must) from the skins, leaving the skins in the fermenter, then returning the juice on top of the skins. This increases oxygen exposure and helps increase extraction of colour and tannins.
Post-fermentation maceration/extended skin contact
Extended maceration times (10–40 days) provide a smoother texture, more subtle tannins, less astringency and more savoury characters.
Shiraz is often matured in oak barrels (either French or American). Maturation in new oak barrels can impart notes of vanilla, smoke and coconut to Shiraz. While many producers still choose to mature their wine in new oak barrels, there is an overall trend towards using older oak (1 or 2 year old) barrels and larger oak vessels such as foudres, which impart a more subtle complexity to the wine.
A foudre is a large wooden vat, which is between 20-120 hectolitres in size (1 hectolitre = 100 litres).
Bottling and ageing
Most Australian Shiraz is bottled with screw cap, with the exception of several high-end wines such as Penfolds Grange.
The ageing potential varies depending on the different style and quality. Shiraz can age gracefully for up to 20 years, and up to half a century in premium examples. Many Australian Shiraz styles are made for early drinking (2–5 years).
Did you know?
Shiraz makes very age-worthy wines, due in part to its abundant tannin levels and flavour concentration. Ageing softens the
tannins and produces a rounded, smoother character over time!
Well, of course, you knew that. It’s one of the reasons you love ours!
But if you’re still not convinced, check out this article which was featured in the Courier Mail this week.
Thanks, Travis (and club member Cath!)!