Maturation Studies So Far

Readers are no doubt familiar with Miles Edlmann, who is responsible for viticultural research and development for Symington Family Estates, and his writing for the Graham’s Port blog when the vines can spare him.  Miles also writes the monthly Douro Insider report which is posted to the Vintage Port Site.  [Update:  The Douro Insiders is now posted in this Blog, and all issues can be accessed through the tab on the menu above.]

Whereas here in the Graham’s blog we naturally focus on the conditions at the five quintas that make our wines, Miles’s Douro Insider report is a summary of observations from across the Symington family’s 27 different quintas which are scattered across the entire Douro DOC region, and of course span the full range of microclimates.  Between them, these estates have 935 hectares (2,300 acres) under vine.  The largest single holding is Quinta do Vesuvio in the Douro Superieor, with 137 ha of vineyard, the smallest is Quinta da Madalena on the Rio Torto with just 4 ha of vineyard.

The full August Douro Insider report has just been posted, but we wanted to highlight this excerpt, which is Miles’s more detailed review of the lab results of the maturation studies.

Apparatus for testing total acidity of the grape must

At this stage the news is as follows: the quality of the fruit appears excellent. There are few signs of fungal attack and the quantity is probably something a bit over average too. Sugar levels are lower than usual for this stage, probably because over the last few weeks temperatures have been above the upper limit for photosynthesis for much of day. On the other hand there is so far little sign of dehydration of the fruit, although slight symptoms of water stress have started to appear in the vines. Some of the basal leaves have dried out but given the relatively still conditions many of them have not yet been blown off by the wind. As a result they are still carrying out an important role in shading the fruit against the brutal sun.

On a very positive note, the seeds were already remarkably dark still well inside August and the skins surprisingly developed phenolically for this relatively low level of sugar. A more usual problem in the Douro is that sugar production outstrips phenolic maturation. Thus by the time the fruit is properly flavour-ripe there is a tendency for it to produce wines that are high in alcohol and care is also required to ensure that the acidity is correct. This year, however, the wines could be extremely well-balanced if maturation keeps following the same path. Currently the Touriga Nacional is looking particularly good as (perhaps due to its late veraison) levels of sweetness are lower than would be expected when sometimes they can verge on the excessive.