September and October 2011 Douro Insider

After a bit of a non-summer came an extraordinary autumn, bringing weather that the gods of grapes wouldn’t have dared to dream about.  With just enough rain falling on the first of the month to refresh the vines and put the final gloss on maturation, we then enjoyed a seemingly endless summer, with absolutely perfect picking weather.  The growing season thus far had brought innumerable viticultural difficulties and some not inconsiderable losses of potential production, so it was extremely pleasing to see that the surviving grapes that did eventually come into the wineries appeared to be in excellent condition. 

September immediately got off to what might have appeared to be a very bad start, with lots of rain on the very first day causing flood damage in many parts of the country.  In the Douro, however, the timing was absolutely perfect.  July and August between them had produced less than 20 mm of precipitation, and the year as a whole was running well below average.  The vines were therefore starting to feel the thirst and definitely benefitted from this moisture (and the accompanying cooling of the air).  Photosynthesis got a boost, and phenolic development picked up too with the grapes taking on a very intense colour.

Within three or four days, however, an intensification of the Azorean anticyclone again began to dominate climatic patterns, bringing several weeks of fantastic (and hot) weather – with several days over 35º C.  And that was it.  Day after day of crystal skies, warm temperatures and a complete absence of clouds followed – even right through the equinox which can often be a time of considerable instability.  The perfect conditions seemed to break on the 28th when a low-pressure trough developed and it was briefly overcast with an insignificant but cooling speckling of drizzle.  Jumpers came out of the drawers for the first time during the harvest, but then they were put right back away again by the next day as normal service was resumed.

A look at the figures unsurprisingly shows some remarkably hot temperatures – including an absolute maximum over 100º F at some quintas (Malvedos included) which is obviously a very unusual occurrence in September.  There were also several places to register what the Instituto de Meteorologia terms ‘tropical nights’ – those on which the temperature does not drop below 20º.  The monthly average in Pinhão, at 22.3º, was therefore comfortably above the mean (21.8º).  Rainfall, at 18 mm, was predictably less than half of the mean amount (40 mm) and by the end of the September just one month of 2011 had provided precipitation levels above average.  The last even moderately damp month was April, meaning that the vines had virtually not seen any serious rain since just after budburst.  On the other hand two significant showers, both of around 20 mm, in the second half of August and at the start of September had the grapes in an excellent condition.

Moving into October, it soon became clear that 2011 was fast turning into the year of the summer that just wouldn’t end.  At Malvedos 14 out of first 15 days of the month registered temperatures over 30º, and a peak above 35º.  Temperatures comfortably into 30ºs were the norm for the first fortnight of October, which sounds extraordinary.  Quite simply, it was hot and sunny, day after day.  Summer finally broke on the 23rd when a depression off the southern Algarve coast began to move inland.  This frontal system brought extremely high winds and, finally, lashings of rain accompanied by a dramatic drop in temperatures.

So as the viticultural year drew to an end with a bit of a whimper, it was of course by then too late to have much impact on the statistics – it was still the warmest October for a decade (18.2º) – or one and a half degrees above average in Pinhão, and rainfall was less than half the predicted amount (34 mm, compared with 76 mm).  This meant that only two months out of the last 12 had been wetter than average (and one of them by only a single millimetre).  This is shown on the figure below:

Note for this month only the graph shows the viticultural year Nov 2010 to Oct 2011

This graph makes it quite clear that a very wet December had to provide really pretty much all the water that the vines had to make use of during this growing season.  A good cumulative excess at the start of the year was gradually overhauled by early May, after which the deficit fortunately increased relatively slowly during the drier months of the year.  We finished up with a total of 546 mm, just under 20 % short of the mean (675 mm).  This meant that by harvest time the vines were under just about the perfect amount of water stress, somewhere between ‘moderate’ and ‘starting to get a little uncomfortable’.

Note for this month only the graph shows the viticultural year Nov 2010 to Oct 2011

The total amount (and distribution) of annual rainfall should obviously not be seen in isolation, however.  The figure above shows that the only really warm months, relatively speaking, came in the spring when the moisture balance had yet to fall below average.  The vineyards then enjoyed a cool summer, with reduced evapotranspiration in June, July and August all mitigating the effects of the drought.  By the end of the viticultural year the mean annual temperature was very close to the average (15.9º) but pushed just above, to 16.2º, by the hot spring.

On paper the general picture was one which suggested a great year for grapes, but the details had all taken their toll.  Three distinct meteorological phenomena had cut production, by close to 100 % in certain vineyards.  Firstly, between mid-April and the end of May conditions had conspired to create no fewer than four situations suitable for triggering primary infections of downy mildew.  Next up came the hail damage in early June, and finally the São João inferno.  What remained on the vines, however, was looking good.

In terms of vineyard activity, the start of September of course saw a continuation of the maturation studies, with plenty of work yet to do both in the vineyards and the laboratory.  In spite of the unusually high sugar levels in mid-August, the phenolic components of the grapes were slow to catch up.  By the time the skins had reached ripeness the sweetness levels were still higher than average even though they had remained relatively static for two or three weeks.  The natural acidity of the fruit had held up well considering the circumstances and was similar to other years when the harvest got underway.  By the middle of the month virtually all of the wineries were ready for action, if not already open, and picking was in full swing.  It immediately became obvious from the fantastic colour of the musts and the rich aromas that filled the adegas that we were looking at a special vintage.  And best of all was the perfect weather, meaning that there wasn’t a rotten berry in sight all harvest.  Unsurprisingly yields were generally down on last year’s bumper harvest but some of the better-run (or luckier) properties produced almost as many grapes, showing that this season’s crop loss was by no means universal.

By the end of September some of the major quintas had already finished picking (which is almost unheard of) and there was even one winery that had closed the reception in time for the public holiday on the 5th October.  Once the adegas had all been washed down and all the wines had been corrected, there was of course an irresistible need for taking a few days off to recover from the rigours of the vintage.  This period varies from quinta to quinta, but usually about a week is enough to give the vineyard workers their energy back.

Pruning may start immediately at this point as there is little else that is pressing in the viticultural calendar.  Otherwise the dead period post-harvest is the perfect time for fertilisations.  Cover crops may also be sown (or re-sown) as deemed necessary, but these three operations are not independent.  If fertilisers are to be ploughed in, the cover crops will of course need to be re-sown afterwards.  On other hand, shredding the pruned canes with the grass or clover seed scattered on the surface of the soil (or even starting to germinate) is clearly not advisable.  For this reason the correct order of operations should be prune the vines, shred the canes, spread the fertiliser, plough it all in and then sow the cover crops.

Ideally pruning wouldn’t start until the vines have lost most of their leaves so that the minerals in them can be reabsorbed into the woody parts of the plant, but quite simply there is not enough time between leaf-fall and budburst to do all the pruning without laying on lots of expensive extra labour.  Plus there is relatively little else to do at this time of year.  It is a good idea then to start the pruning with the Tinta Roriz if one must begin early.  There are two reasons for this: the first is that the Roriz tends to be the first variety to drop its leaves and the second, which may or may not be related, is that it is the variety with the most brittle canes.  This makes it a charm to prune but a nightmare to train.  Accordingly it is very rare to come across cane-pruned Roriz, since the canes would much rather snap off in your fingers than be bent down and tied onto a wire.

But whilst the viticultural calendar might not be overflowing at this time of year, the olivicultural one is just warming up for its culmination.  Or not, depending on one’s evaluation of the economics of olive production.  The ready availability of good quality (but imported) olive oil made from intensively farmed, irrigated and mechanically harvested olive trees means that the Douro has a tough time competing, in spite of the excellent quality of the oil produced here.  As a result unfortunately much of the olive crop is simply left on the trees to come down with the wind.  This is of course a huge shame, particularly since there is a fair load of olives this year, especially on the lower branches (which makes picking faster).  Although, much like the grapes, this year’s production is less than last year’s in general.

One way of increasing the value of the olives is to turn the olive groves over to certified organic production.  Since normally no chemical treatments are carried out anyway, most of them are at least half-way there already.  Complete elimination of herbicides is required, however, which is why (for those who had decided to pick) much of the October was spent working under the olive trees with strimmers or mowers to cut back any vegetation that might otherwise impede spreading the nets into which the olives will fall after being knocked off the trees.  Time was short, however, as like the grapes the olives began to change colour very early this year.

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  1. Time was short, however, as like the grapes the olives began to change colour very early this year

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