August 2009 Douro Insider

The weather in August was not especially interesting, other than to mention that it turned out comfortably warmer than average in spite of one thundery week. It was also notable in that it contrasted considerably with July – a month that clearly disappointed those who enjoy sunny conditions for the start of the holiday season. Although relatively consistent, the weather was not without its hiccoughs, especially in Gaia and Porto. Indeed, as Britain’s much hyped ‘Barbeque Summer’ evaporated (or perhaps dissolved?) in rain the wider implications of this Europe-wide bad spell were felt here as well. As a result, the hot start turned decidedly unsettled around the time most people in the wine business were returning to work after the break (around the 17th) and there were some overcast mornings which followed very cool nights. The hurricane season getting underway in the western Atlantic meant that the first of the summer thunderstorms were felt in Portugal. As far as the Douro was concerned very little of any consequence actually happened, although there were reports from Lamego of hail falling in a fashion that didn’t much damage the vines.

After the sun came out again things became very hot indeed, almost all the way to the end of the month. This was due to a typical Iberian weather system often occurring during the summer. Heating of the land mass creates a cyclone known as a thermal low which is complemented by an anticyclone out in the Atlantic, resulting in ongoing clear skies and high temperatures, according to our friends at the Met Office.

What was especially worrying for the vines during this period was that there was no respite from the heat at the end of the day, and as the winds picked up in the evening it felt like staring into a hairdryer. This ongoing dry heat, combined with the lack of water in the soil, persuaded the vines to take slightly desperate measures of self-preservation. In order to reduce evapotranspiration the older leaves (the ones closest to the end of their productive cycle) are shed, simply drying to a crispy brown and dropping off. The problem is that these older leaves are of course the ones nearest the base of the shoots (which is also the fruiting zone) and even when past their prime they still provide an important service by keeping the worst of the sun off the grapes. Once the bunch zone has been left exposed it is natural that the fruit will suffer some dehydration, and the first signs of fruit shrivelling started to appear on the South westerly side of the vines.

There was a brief spell going into the last week of month characterised by a notable cooling of temperatures, and this was especially felt on the coast. It spotted with rain (literally, just a few spots) both in Porto and in the Douro, but this was not nearly enough to penetrate the thick dust. Meanwhile towns in the interior north, including a village close to Pinhão, started running out of water altogether and for some their daily needs now have to be supplied by fire brigade tankers. The official figures put 34 % of the country under severe drought, and state that 37 % of the land area is suffering from moderate drought.

With regards specifically to Pinhão, August started coolish, warmed up steadily over the first two weeks to very hot, and then basically stayed there, the only exception being a couple of days at the start of the last week. To get an idea of just how hot it was, there were a remarkable 15 days, or half the month, reaching 35º C. Out of these, two days topped 40º. This gave us an average temperature of 25.8º which is considerably warmer than the mean, standing at 24.6º. Taken in comparison with a relatively cool July, it meant that monthly average temperature jumped by more than 2.5º. Normally speaking July and August are almost identical in terms of temperatures.

But perhaps we should beware of exaggeration – both 2005 and 2006 were considerably hotter than 2009 in every month from April onwards. Furthermore, in 2005 the total precipitation for the agricultural year had not even reached 200 mm by the start of September – and we have already had double that this year. So whilst it was a hot and dry month, things may not be as extreme as they might seem. The absolute high was 40.2º, and the low a reasonably cool 13.8º. Precipitation was negligible; only 2 mm of rainfall was recorded (the average is 17 mm but then August often brings thunderstorms). This figure is predictably the lowest monthly value registered so far this year.

From the usual graph we can see that the cumulative annual rainfall currently stands at just under 300 mm. Compared with the average, this gives us a rainfall ‘deficit’ for 2009 that is now more than 100 mm. And significantly, we have had a total of less than 60 mm over the last four months.

As far as the workers in the vineyard go, August is the time to take a long and well-earned summer break to recharge their batteries before the rigours of the harvest. This means that all that remains in the quintas is an absolute skeleton staff, if indeed there is anyone at all apart from the caseiros (the vineyard managers, who usually live on site). Basically someone has to be around to mind the property, but little else. There is not much that can be done to help the vines at this stage of the year. In one or two cases a few people did stay on to irrigate 2009’s new plantings, but this was an exception rather than the rule. When the area is extensive it takes a long time to hand-water every single rootling. Otherwise it was just general housekeeping to stay busy: hortas (vegetable gardens), pomares (orchards), cutting firewood and general maintenance all featured in some way.

The real business of August of course begins in the second half, when the all-important maturation studies get underway. We need to find out quickly how the grapes have been ripening whilst we were on the beach, so the usual team of estagiários (people on work experience) and other temporary workers gets to work immediately. Under close supervision they collect dozens of grape samples every day from the various quintas, by variety and location. These are analysed in the lab for Baumé, pH, titratable acidity, berry size and volume and colour. Once armed with this information, we are able to determine when to start picking and in what order to harvest the different parcelas.

It immediately became apparent that sugar levels were much higher than expected, suggesting an early start to the vintage. On the other hand, phenolic maturation was not particularly advanced and the colour of the musts was unimpressive. Should we wait for phenolic ripeness but run the risk of too much sugar and possible dehydration of the fruit? Or would this be too much to hope for, given the water stress the vines are already suffering? The timing of the harvest will be critical in order to get the best out of the grapes and avoid producing unbalanced wines, but as ever we are optimistic. There is absolutely no sign of mould whatsoever, and the sanitary state of the grapes is excellent.