August 2008 Douro Insider

Another month goes by, and with it come more strange climatic patterns.  All across Europe reports were pouring in of appalling weather so in many respects we were lucky that the worst the Douro suffered was one wet weekend and some rather cool temperatures.  The month kicked off with a freak tornado in northern France which killed three people on the 3rd, and then another one hit Poland 12 days later with the same death toll.  In the UK they were also having a horrible time with one of the worst summers on record.  Over there August was phenomenally wet and the sun barely appeared.

Fortunately, from our privileged vantage point in the heart of the Douro, most of this prevailing westerly weather was blocked by the Marão range and, although strong upriver winds pushed some of these clouds inland over the hills, only a tiny amount of the rain actually arrived in the vineyards.  But beyond the hills, where lies the coastal plain running down to the mouth of the river and the Atlantic beyond it, the good citizens of Porto were not much better off than the English.  During the first couple of weeks of the month they too were cursed with a miserable start to the summer holidays, with plenty of cold, wet and gusty days.

Although the days in the Douro were generally fair it would best be described as a predominantly breezy month.  There was far more wind than usual and of a different nature: it was very much cooler than what might have been expected.  There were none of the hot easterly or southerly winds that sometimes sear the summer months with really high temperatures.  This is obviously kinder on the vineyards since cooler and damper winds are less likely to dry out the vines (especially given the recent lack of water) or to cause them shut their stomata and close down photosynthesis.

To summarise, it was simply surprisingly cool for a Douro summer, especially during the evenings.  There was no need whatsoever for the outdoor furniture because it was too cold to sit out at night – an uncommon state of affairs.  The dramatic amplitude of daily temperature fluctuations that July had hinted at continued, although it is generally considered that from the point of view of grape maturation this is beneficial as it helps the fruit to retain good acidity.

The consistent winds and lack of rain exacerbated the already extremely dusty conditions.  Apart from one wet Saturday in the middle of the month there was no precipitation to speak of but an oddly dry thunderstorm on the 28th made things unpleasantly sticky for a couple of days.

Total rainfall for August in Pinhão was just under 5 mm – less than a third of the average which stands at 17 mm.  This was therefore our third consecutive month of almost complete drought – only 8 mm of rain has fallen since the end of May (consider that the average value for this period is 63 mm).  One can only be grateful that it wasn’t hotter or the vines would have been looking very sad indeed by now.  In terms of the total for the calendar year we have only had 20 mm less than average, with 368 mm, but virtually none of it has been recently.

As we have mentioned, temperatures were relatively benign.  The mean for Pinhão was 23.7º C for the month, one degree cooler than the mean (24.6º).  In the light of July’s figures, that means that the two hottest months of the year have both been one degree below average.  The hottest part of the month was right at the start when an absolute high of 39.3º was reached, and then things cooled down a bit and stayed relatively stable.  There was a week during the middle of the month when it didn’t even rise above 30º (something almost unheard of for August) and it dropped to a low of 12.1º.  It was at about this time, around the 16th, that a tiny amount of rain fell on two days.  In all there were nine days climbing above 35º and seven on which it dropped below 15º.

August in the vineyards is a very slow month for some, and for others a month of two halves.  The diários (vineyard workers) are, almost without exception, away on holiday all month and so virtually nothing at all is going on at the quintas, at least to start with.  Most properties operate with only a skeleton staff of caseiros (farm managers) and maybe a tractor driver, and even then they may spend much of their time on housekeeping duties such as maintenance, tending the vegetable gardens, looking after the animals and maybe cleaning up the orchards and olive groves.  Therefore, predictably, there is not a huge amount to report.

Weed control featured slightly, with some minor herbicide applications or ploughing carried out.  Due to the speed at which the vines can develop at this time of year, canopy management is too important a task to abandon completely at the very large quintas.  Thus there were also despontas (see July’s report) going on at some of the bigger properties, and occasional insecticide applications as the struggle against cicadela (ditto) continued.  Thankfully all such treatments have met with success so far this year, although it has not been easy.

There is one activity which must always be carried out in August, but more often in some years than in others, and that is of course hand-watering this year’s new plantations.  The fact that there has been virtually no rain for three months means that watering takes on a special significance in 2008.  Without these regular irrigations the young vines would have no hope of surviving their first year.  All new plantations were therefore watered once or twice.

Maturation studies got underway as soon as the technical team returned from holidays in the middle of the month, assisted by the usual assortment of estagiários (work experience students).  It immediately became apparent that the phenological cycle of the vines this year was going to be a long one.  Remarkably, it was very easy indeed to find bunches that were still going through veraison even into the last week of the month.  This was particularly the case in the higher parts of the Douro.  Given such late veraison, it is inevitable that maturation and of course harvesting will be delayed.  As the results of the first analyses began to come in, they did indeed confirm what was already obvious to most people: sugar levels were very low for this time of the year.

On the other hand, acidity was predictably but pleasingly high because of the cool temperatures and there was very little sign of the basal leaves drying up on the vines.  This meant there was a larger leaf surface area available for photosynthesis than usual since a hot summer typically brings a certain degree of premature leaf fall and therefore an associated reduction in canopy size.  This detail bodes well – and theoretically at least rapid ripening should occur given the right conditions.  The phenolic development of the berries was not bad at all, with the tannins in the skins starting to soften in spite of the low Baumés.  At the very least, the grapes appeared to be undergoing a balanced maturation, and there was no sign of disease whatsoever in our vineyards.

If there was cause for complaint it would be that the vines are rather too good at thriving on very little water because, irrespective of the drought they are suffering, the berries are still a little too plump for our liking.  A slight degree of dehydration would be very welcome.  Right at the end of the month came another hot spell which finally brought with it warm night-time winds too.  Could this be enough to really concentrate the fruit which is, potentially, of excellent quality, and deliver another fine vintage? We are already about 10 days behind schedule and so a fine and hot start to September would be very welcome.

On a final note, we regret that the next Insider’s Report will be posted rather late.  All of our viticulturists are also trained winemakers, and will soon be spreading out to take charge of various wineries across the Douro where we have every intention of making some top quality vintage port.  Unfortunately this means that there will not be time to write a report in September.  Instead the next report will be posted some time in November, covering both September and October, and reviewing the vintage.  It will also include a round-up of the climatic data for the agricultural year.

Have a good vintage!