This week officially begins the countdown to the harvest for Graham’s port wines. All our winemaking and viticultural team will have had their holidays, and this past Monday we began our maturation studies.
Every week from now through the start of harvest, we will collect samples of grapes from all our quintas and then analyse the samples in the lab to assess the maturity of the vineyards and plan when and in what order we will harvest the grapes for Graham’s port wines.
In the morning, teams collect samples of 200 individual grapes from each designated vineyard (or parcel) at each quinta. For example, at Quinta dos Malvedos we collected from three different parcels of Touriga Nacional – one just below the house, another halfway up the ampitheatre-like property, and another from a parcel at the top of the hill. Similarly we collected berries from three different parcels of Tinta Barroca scattered around the property, and then the team moved next door to Quinta do Tua, across the Tua River from Malvedos, and collected grapes from one parcel of Touriga Nacional and another sample from our vinhas velhas – the old mixed-variety vineyard.
To get a truly representative sample, the berries are plucked from grape clusters on both sides of a row of vines, from clusters at top and bottom of vines, from clusters buried in leaves as well as those more exposed to sun. We may include some green berries and also some berries that may have begun to dry out and become like raisins. Once we have 200 grapes from the parcel, the bag is sealed, marked as to its origin and stored in a cooler until it is delivered to the lab.
Every week until harvest we will collect samples of 200 berries each from these same vineyards, run the same set of tests, and accumulate data for weight, juice volume, Baumé, total acidity, pH, colour and taste. This early we expect to see lower sugars and higher acidities than later in the season, when that relationship will reverse. Based on this week’s sampling, we can begin to make our harvest plans, which will be fine tuned each week as the assessment continues.
In the lab, each 200-grape sample goes through a pretty simple and straightforward process of assessment: After weighing the sample, we roughly crush the grapes by hand in their collection bag, then press them in a miniature wine press and run off the must which is then centrifuged and measured for volume. Finally, the must is poured into wine glasses. Three chemical analysis tests are now performed, to measure Baumé, which is indicative of sweetness and alcohol levels, to measure total acidity, and pH. Two low-tech tests are also performed: we look at it to assess the colour, and we taste it to have a sensory impression to weigh against the test data collected.
Not all our testing is done in the lab, however, nor are our plans and decisions all based on lab results. The ultimate deciding factors are human. We draw on our own personal experience, as well as the historical records of the experiences of all the Symingtons and Grahams who have harvested these vineyards before us. Charles Symington, our head winemaker, will now spend most of his days in the vineyards looking and assessing their condition for himself and tasting the grapes as he goes. More from Charles and his preliminary assessment of conditions in an upcoming story.