Making Sauvignon Blanc wines

While every winemaker has their own ideas on producing Sauvignon Blanc, the instructions given here are typical for many in the Marlborough region.

Reductive handling in the vineyard
Grapes are machine harvested, loaded into Gondola's (5 tonne tractor driven hopper trailers) before being transported to the winery in 10 tonne trucks (and trailers -10 tonne also). The Gondola's act as buffers between the harvester and the trucks allowing a seamless flow from vineyard to winery. Depending on the producer, potassium metabisulphate may be added to the Gondola's to prevent oxidation. The rate is typically 100g per tonne of grapes and given normal handling this will result in 25 mg/l Free sulphur dioxide in the pressed juice. Ascorbic acid may also be added at a rate of 40g per tonne but it is important that sulphur dioxide is present, otherwise the juice will undergo hyperoxidation.

Good organistion minimizes "time on skins"
It is typical for grapes to be transported to the winery by truck and sometimes truck and trailer. The reductive style of winemaking requires that the grapes be pressed as quickly as possible and not be allowed to sit on skins for any time. Each press (8000 litres) processes up to 12 tonnes of crushed/dejuiced fruit. This amount is approximately one truck load. Larger presses (15,000 litres for example) require multiple truckloads to fill, and all the while the second load is being picked and transported to the winery, the first load is sitting "on skins" in the press. Extraction of astringency during this time needs to be removed later in an operation that could have been avoided. It is said that the precusors of desirable flavour compounds are prone the oxidation and while not volatile themselves can be destroyed, thereby not allowing them to develop during fermentation.

All press fractions blended together
When pressing grapes, the first juice is the purest. As the pressing intensifies, more of the flavour, colour and astringency are extracted from the skins, stems and seeds. Depending on the style of wine this may be benefitial. Generally speaking, lighter fruity styles tend to avoid hard pressings while bigger, more robust styles often require these elements. Marlborough Sauvignon Blanc fits into the first category and is known for it's fresh passionfruit/tropical characters (with underlying fresh cut grass), a smooth fruity/herbal taste and long crisp finish. Gentle handling results in grapes/bunches being largely intact when pressed and this yeilds purer juice. Grapes that have been crushed and torn and are pressed as a sticky slurry have typically highly flavoured and coloured (brown) juice and course astingency, especially the juice at the end of pressing (pressing fraction). As handling techniques have improved over the years the quality of the pressing "fraction" has improved to such an extent that it is now common practice to incorporate all juice together in one tank. Two benefits from these improvements are firstly, from a logistical point of view, it is much more efficient if only one tank needs to be prepared to recieve the juice and from a quality point of view, a higher pH (resulting from incorporation of the pressings fraction)provides are envirnoment in which the volatile precussors of the desirable fermentation characters are more stable and don't degrade as regularly.

Flavour enhancing yeast

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