Machinery maintenance is key to vintage success

Machinery maintenance is key to vintage success

WEATHER IS VITAL to a successful vintage, not just at harvest but throughout the year. But we cannot rely on nature alone. To achieve the crucial balance required for a great vintage, winemakers must plan ahead to ensure fruit quality is not severely compromised by equipment failure, rather than a bout of bad weather.
Imagine this scenario. You've forecast optimal harvest schedules to maximise the utilisation of your crushers, pressers and fermenters, but during a crucial stage of vintage a key piece of machinery breaks down.
Juniper Estate winemaker, Mark Messenger, is all too familiar with this situation and after 15 vintages at this Margaret River winery, has fortunately only experienced serious equipment failure on two occasions - both involving the press.
'The first breakdown occurred when the press was new and the technician was unavailable to commission it before the first press load. We were about a third of the way through the cycle and there was an almighty bang as the drum spun out of control because the bolts on the rotation motor had worked loose during transport, ripping it from its mounting. Luckily, we were able to get it fixed quickly by local tradespeople,' Messenger explains.
The second was a split in the press membrane a few years later, but this time Messenger was able to patch it up, as the lead-time on a new membrane was three weeks.   
Messenger and his team have certainly learnt from those experiences and undertake a combination of internal maintenance and specialised contractors to service its equipment pre-vintage.
'The key is to test all machinery at least a month prior to the start of vintage so there aren't any nasty surprises,' he adds.
'It is not viable for a small winery such as ours to have back-up vintage equipment, so that is why servicing is so important. Over the years as the Margaret River wine industry has grown, so too has the ability to source spare parts for our equipment. In the early days, if you couldn't fix it yourself you were in dire trouble and that's where it pays to be on good terms with your neighbouring winery.
Despite even the best maintenance program, machinery does have a use-by date, which is why Juniper Estate recently changed its receival hopper from a screw type to a vibrating hopper to achieve gentler handling of grapes. This move has seen the winery achieve positive results with its wines, due to there being lower phenolic pick-up and minimal juicing prior to the destemmer.
'A few years ago we also invested in a mechanical sorting machine, mostly for use on red grapes, and I have found it a wonderful tool for reducing green matter and overripe/damaged grapes from entering the fermenter. It works quite effectively in removing most petioles, shot berries, leaf matter, stems, shrivel and even insects from hand- and machine-picked grapes,' says Messenger.
'I have observed a significant decrease in astringent phenolics and green vegetative characters in our red wines since its commissioning. The addition of the vibrating hopper has also further enhanced its effectiveness.'
Juniper Estate uses a combination of hand-picking and machine harvesting for its fruit. Its premium batches are hand-picked because they are selective picks and small in batch size, whereas machine harvesting is favoured for most of the varieties in its second tier wines. Messenger says this is purely a matter of cost efficiency and the ability to pick them in the coolest part of the night or day to maintain freshness.
'We use a contract harvester and this year we will be trialling a harvester with on-board sorting, which is expected to further lift quality by greatly reducing matter other than grapes,' he says.
Fraser Gallop Estate's winery facility was built five years ago under the watchful eye of winemaker, Clive Otto. This winery was built with the capacity to process slightly more fruit than originally anticipated and features the latest equipment, including a TurboPiguer.
Otto says this machine is one of the gentlest ways of pumping over red ferments.
'The TurboPiguer allows one person to do all the red ferments without the need for assistance, while at the same time temperatures and baumè levels can be checked, and any necessary additions can be made,' he says.
'We are finding that one pump-over a day is generally sufficient. The TurboPiguer is able to pump whole, intact grapes without grinding pulp and skins at up to 70,000 litres/hour, allowing better homogenisation and extraction of the must. This is equivalent to two tank volumes initially backing off to twice a day pump-overs to equivalent half a tank volume below 2°Be. We are thrilled with the outcomes in terms of tannin profiles of the resulting wines.'
The winery has only experienced one serious breakdown with the TurboPiguer, when its motor exploded on a Saturday morning mid-vintage. Fortunately, Otto was able to borrow a tank torpedo from a winery down the road until the machine's motor was able to be repaired on the Monday.
Although the winery is still quite young, Otto is always on the lookout for new technologies and efficiencies in both the winery and the vineyard.
'We may consider a peristaltic pump in the near future as it's the gentlest pump available. The pump works rather like a human intestine or snake, as the substance moves along in a peristaltic fashion, ensuring the grapes don't get smashed as much in the process. Whereas, our existing mono-type pump has some shearing action that could crush seeds and skins,' Otto explains.
'Sorting tables are another potential investment for us, as they will further improve quality so that only the best grapes make it into the fermenter. They will allow us to select out green, diseased or damaged grapes. You can also eliminate vegetal material like stalks, petioles, canes and pests, such as snails.'
Otto also has his eye on a Delta Oscillys 100 Destemmer. This machine operates without beater shafts or rotating cages so it removes grapes from the stem by a swinging motion and the grapes fall off the stems with less juicing.
'The berries are more intact, the stems are more preserved without crushing or grinding, and the machine comes with a sorting table incorporated to take out petiole and vegetal parts. It is up to 10 times more qualitative than our existing destemmer,' he adds.

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