'Great wine comes from great grapes.' Dry River is not unique in following this tenet, but it is unusual in how it sets out to do it. The initial and crucial decision for the winemaker is the choice of the vineyard site. Having established which region is cool enough to preserve varietal and fruit characters, yet warm enough to get the fruit ripe in most years, the winemaker must seek out those locations which have the appropriate combination of low rainfall and soil moisture storage capacity. It is widely (though not universally) held that deep, free-draining soils of sufficiently low vigour and moisture-holding capacity for the vines to start to experience moisture stress as the grapes ripen are desirable. Deep soils allow the roots to forage deeply in search of water and to remain well removed from surface water which can be so damaging during a wet harvest, causing berries to swell, split and succumb to botrytis rot.
pursuing quality the dry river way
Once the site is chosen and the vines planted, it can be a number of years (in my view about 8) before the vine is able to start producing a quality product. After this, the meticulous and expensive process of optimising the results of the choice of site and varieties starts in earnest.
- Training the vine foliage or canopy is critical, since shading within it reduces the ability of the leaves to work properly, encourages disease and tends to produce less desirable flavours. On our Estate we employ a training system called Scott-Henry which divides the canopy in two, allowing half to grow up and half to grow down, thereby doubling the canopy's ability to use direct sunlight. The disadvantage of the system is that it requires a high labour input and when combined with our shoot positioning and leaf-plucking (discussed later), it can result in operating costs two or three times higher than those of more production-orientated, machine-tended vineyards.
- In conjunction with favouring open canopies, we place considerable emphasis on exposure of the fruit to sunshine for the production of riper, more generous flavours; a higher proportion of 'bound flavours' in the wine which will emerge during cellaring, and a dramatic improvement in the health of the grapes during difficult years. This is achieved during early summer when teams of school-children and adults descend on the vineyards to pull off every leaf around every grape - by my calculation, probably 80,000 - 100,000 leaves every season! Leaf-plucking machines are a poor substitute for the TLC of homo sapiens in this task.
- The grower must balance the crop yield against the canopy produced by the vine during the season. If the cropping rate is too high, flavour development is retarded and the wine can lack concentration. We must limit most yields to less than 3 tonnes/acre for the average year. Commercial tonnages for New Zealand are commonly around 4-6 tonnes/acre, with varieties such as Riesling sometimes cropped up to 10 tonnes/acre; in the latter case, the depressed quality may still take a year or so to be evident in the wine. As an example, this year at veraison (late February) we thinned the Riesling by 50%, Pinot noir by 30% and Chardonnay by 2-10% to maintain crop levels within our target. Crop thinning at veraison is not uncommon in quality-orientated French vineyards.
- Irrigation can be a choice for many vineyards which wish either to protect themselves against the risk of damaging drought or to sustain routinely high cropping levels. We prefer to avoid all irrigation to encourage roots to seek water deep in gravels (reducing risks from surface water after recent rain) and to encourage more drought stress later in the season, thereby producing more concentration and weight in the final wine. The commercial downside of this decision is frequently smaller berry size and lower juice levels per tonne. By 1 April of this year the extreme drought was making our no-irrigation philosophy look rather foolish. By 7 April the rain had arrived and irrigation was a bad joke. It was notable that berry size in our vineyards remained small; berry splitting and rot was not a problem, as it was in some other vineyards, and wine flavours indicate there has been no loss in concentration.
The combination of crop limitation and lack of irrigation can cause large reductions in the number of bottles attainable per acre of vines. Because of this practice, our final yield of wine can be 25-35% that of other commercial enterprises. What some viticulturists may view as rather 'eccentric' or 'extreme' canopy management can also cost considerably more than that of more commercially inclined operations. The merits or otherwise of these practices are the subject of passionate debate by winemakers (and even some viticulturists!) - winemakers are nothing if not rugged individuals. However, the important question is so frequently missed … can the consumer taste the difference?