Viticulture

Weather impacts wine

By Vanessa Wiltshire

The wine region of Heathcote is diverse and unique.

Tucked against the Great Dividing Range beyond Melbourne, the Heathcote wine region spans 100km from Tooborac to Colbinabbin.

It contains variety of soil profiles, including the 500-million-year-old Cambrian volcanics, and there are several micro-climates.

Combined with the passion and creativity of local winegrowers, Heathcote wine (particularly shiraz) presents with a depth and complexity not seen elsewhere in Australia.

Some say even the world.

Over recent years, Heathcote has risen in prominence as an acclaimed wine region.

What many don’t know, however, is that many varietals, both French and Italian, are performing well. From marsanne to vermentino, riesling, rose and nebbiolo to sangiovese — these are just some of the unsung favourites.

With 50 winegrowers in the region, the outlook is bright.

But there are clouds.

Increasing numbers of viticulturists say changing weather patterns — longer, hotter summers and warmer, drier winters — are having an impact on crop yield.

Heathcote Winegrowers Association president Ian Hopkins said, ‘‘general observations of the 2019 vintage seem to be that it was a tough year, but better than expected’’.

Viticulturist and manager at She Oak Hill Estate, Jane Leckie, said weather patterns leading up to the 2019 vintage had ‘‘made things a challenge’’.

Producing shiraz, chardonnay and rose, She Oak Hill is a boutique vineyard under 7ha, five minutes north of Heathcote.

‘‘The weather conditions in 2018 meant that many of the shoots on the branch stopped growing. Or, they grew too early,’’ Ms Leckie said.

‘‘This shifted our 2019 season entirely. The fruit ripened earlier and faster; we were picking in February as opposed to March or early April.’’

She said earlier vintages were becoming a trend and not ‘once-off’ events.

‘‘The biggest challenge at She Oak is not knowing what each season is going to hold.

‘‘I believe weather patterns are changing. To counteract this, we are reducing the crop before fruit starts to drop.’’

The technique is called ‘layering down’ and is done during pruning.

‘‘It takes the stress off the mother vine by leaving less buds. Instead of 10 or 11, we prune to around eight,’’ Ms Leckie said.

She Oak Hill Estate is dry-grown, meaning the vines are not irrigated.

While the technique can lead to a fuller bodied wine, the greatest challenge is that the sugar level of the fruit can’t be controlled as it ripens.

‘‘When the grapes are ready to be picked, they must be picked,’’ Ms Leckie said.

‘‘This is starting to happen earlier every year.’’

With a reduced crop, she hoped for greater quality and yield.

‘‘Rainfall over autumn and winter this year has been much better than it was in 2018.

‘‘But it’s topping-up-grass water. We’re after a deep soak into the root system, which is about a metre-and-a-half into the soil.’’

Ms Leckie believes the increased rainfall this year, combined with the layering, will lead to a greater yield in 2020 — but she can’t be sure.

‘‘Viticulture is like any other kind of farming. You don’t just sit around and watch crops grow.

‘‘It’s about thinking of creative ways to solve problems.

‘‘However, that’s the part I enjoy the most.’’