156 Port anD the Douro
Wines set aside to become part of this chain of old tawnies are selected from among
the finest Ports, usually after making up the potential vintage or single-quinta vintage
lotes. The component wines are mostly sourced from A or B-grade vineyards in the Cima
Corgo or Douro Superior but a number of quintas in the Baixo Corgo are making some
good wines of their own. Individual shippers look to maintain different house styles, but
on the whole the young wines destined to develop into mature tawnies combine stature
and structure with elegance and finesse.
The ageing process is of crucial importance to the style and character of tawny Port.
In small casks (lodge pipes) of 600 to 640 litres the wine undergoes a gradual process of
oxidation and esterification as the colour fades and ethyl esters and acetals develop in
the wine. The formation of these volatile components (sometimes known colloquially as
vinagrinho, ‘little vinegar’) is directly influenced by the ambient storage temperature and
rate of evaporation. Consequently, tawny matured in the Douro undergoes a different
(and more rapid) maturation process than that aged in the cooler lodges of Vila Nova da
Gaia where annual evaporation (mainly of alcohol and water) is between 1 and 2 per cent.
Provided the wines are well nurtured, a degree of so-called ‘Douro-bake’ can be a positive
advantage in a mature tawny. A higher rate of evaporation (around 3 per cent a year)
concentrates the natural residual sugars and the higher temperature produces wines with
a distinctive toasted richness. One single quinta making their own ten-year-old tawny
estimates that keeping the wine up in the Douro accelerates the ageing of the wine by
around 30 per cent. Many shippers deliberately use a component of Douro-matured
wine in their aged tawnies, although they have also constructed purpose-built lodges with
controlled humidity to emulate the conditions found in Vila Nova de Gaia.
The racking regimen (see page 145) is also very influential in the development of the
wine and provides the tasting room with a regular opportunity to monitor the character
and evolution of each lote. The tasting and blending of tawny Port is a continuous
process, the aim being to produce a wine that both conforms to the house style and
is also consistent over time. Wines set aside initially are often marked with the year of
the harvest but as the shipper makes up new blends followed by blends of blends, the
characteristics of the individual wines gradually meld into the house style. Lighter, earlier
maturing wines will go towards a ten-year-old blend with richer, more structured wines
reserved for older tawnies (see individual styles, below). Stocks of old tawny Port are
largely driven by anticipated sales and the onus is on the shipper to look over forty years
ahead in order to put aside the correct quantity of wine. If there is a run on stock, the
house style may waver and it is not unknown for shippers to trawl the Douro in search of
old wine. Occasionally a slightly caramelised, rancio character can enter a wine that was
otherwise a textbook tawny. The final lote may be made up of anything between ten and
fifty different component wines with younger, fresher, fruit-driven Ports balancing older,
mature styles that have gained more in the way of secondary complexity from extended
ageing in wood.
I am by no means alone in my admiration of the intricacy and poise in a well-aged
tawny. The Port shippers themselves often drink a good tawny in preference to any