The tender care and hard work we put into our vineyards bear fruit – literally – in the October harvest. Photographs taken in 1900 show that virtually nothing has changed; there is the same hustle and bustle of trailers laden with baskets full of grapes, the same enthusiasm to work. Whole families of harvesters come from Portugal as well as Spain, returning year after year, and we have started building a house on the edge of the Tondonia vineyard where they will stay during the harvest.
The basis of a fine wine is harvesting by hand, bunch by bunch, which no machines could duplicate. Cutting by hand, with the curved knife called "corquete", prevents the grape breaking and releasing must that could ferment prematurely. Ensuring that the grape skin is not broken is aided by the emblematic containers made in the López de Heredia cooperage, which have a capacity of just under a hundred kilos. Thus begins the discourse between grape and wood that goes on for years while the wine is maturing.
The last part of the grape harvest takes place when the containers are emptied into the weighing machine - in hoppers. From there the grapes pass to the destemming machines, which gently break the grapes to extract the must. This must comes into contact at once with the yeasts on the grape’s thin waxy coating.
As mentioned earlier, harvest time at López de Heredia is hectic, but organized in such a way that there is no delay in receiving the grapes arriving in the containers via tractor-drawn trailers. It is essential that there is no delay because waiting can produce very prejudicial fermentation in the containers.
This is why there is a harvesting train for red grapes and another for the white. Red grapes are destemmed before going to the fermentation vats, while white grapes are crushed, thus immediately releasing their must - it is undesirable that the must should be in contact with skins.
The difference between red and white wines lies in the fact that with red wines fermentation occurs while the liquid is in contact with the skins, which contain the colourant, whereas with white wines the must ferments on its own. With rosés, the process is mixed: the skins remain in contact with the must during a period of maceration (soaking) so that some of the colour can be absorbed, but are then removed before fermentation begins.
The must is fermented in large oak vats. The biggest, with a capacity of 240 hectolitres, are for red wine, while the smaller vats (60 hectolitre capacity) are for whites. Yeasts are vital to the quality of the wines since they cause fermentation; these micro-organisms are typically found in the soil, and are spread over the grape skins by insects and the wind. The main microflora in La Rioja are Scharomyces, Kloekera apiculata and Tomlaspora rosei.
During the biological process of fermentation carbon anhydride is emitted as the sugars are transformed into alcohol. Although the temperature never exceeds 36ºC, bubbles disturb the surface of the vat as if it were boiling - hence the popular term of "tumultuous fermentation".
During the vinification of the red wines, the solid part of skins and pips (the marc) form a thick floating layer called a cap, which has to be circulated in order to activate the oxygenation of the yeasts. This process of “pumping over” makes the maceration more homogeneous and helps the extraction of colour. The tumultuous fermentation usually lasts about seven days, during which time the must becomes wine. However it maintains a certain percentage of residual sugar which has to be removed in a slower subsequent fermentation.
Before initiating the second fermentation for red wines, the wine is drained from the vat in order to separate solids from liquids. This second fermentation should take place in Bordeaux-type oak barrels, and can take up to five or six months. The result is a softer, more perfect wine.
Once wines have been through both fermentation processes, and the sediment or lees have been removed, the wine is then ready to be aged in 225 litre Bordeaux size barrels in our underground cellars, in conditions of perfect temperature and absolute tranquillity. All in all some 14.000 American oak barrels are perfectly ordered in the 6.000 square metres of cellar space.
During this period, a very slow process of oxidation (esterification) takes place through the pores of the wood, which play an important part in the development of the wine’s bouquet. This biological process is complemented by periodic rackings (once or twice a year), to remove the sediment that settles in the bottom of the barrels. Our rackings are carried out with rigorous precision, so that the impurities are in contact with clean wine the shortest time possible. It goes without saying that the barrel is never turned up to stand vertically throughout the racking process.
In other words, anything that might prejudice the good evolution of the wine in question is painstakingly removed, while the elements that contribute to flavour are kept.
Ageing wines should be seen as a pedagogic act; the wine is “educated", and hence should never be rushed through speeded-up improvisations which would destroy the biological process which give it its character. Wines need to spend a minimum of three years in barrels to begin to manifest their “education”. Ten years is the maximum barrel ageing permitted in the Rioja Alta region, and anything more than six years is unusual unless the wines are destined to become Gran Reservas.
Bottle ageing is a process of reduction which gives a wine that has undergone excellent wine-making and barrel-ageing processes a certain smoothness and an infinite range of aromatic nuances that constitute its bouquet. Even our most commercial wines spend a minimum of six months ageing in our cellars before being released for sale.
More commercial wines are the result of blending of various vintages to obtain an average age, a process which is carried out at the end of the barrel ageing process. Gran Reserva wines, on the other hand, which have spent many years in bottles, are not blended. The year of their vintage is shown on the Appellation region label.
Not all vintages are chosen to be "great wines"; two or three per decade at the most are chosen because of their excellence. Making these wines takes at least seven years, at the end of which they are clarified with fresh egg whites. They are then immediately bottled directly from the barrel, without any filtering, and closed with a long cork.
The corks are further sealed with wax to prevent any contact with the exterior during their many years in the cellar. It is only in this long rest period that they acquire the category of "Gran Reserva", like perfect gentlemen who have nobly grown old, while still maintaining some of their youthful characteristics.