White wines

The fermentation process for white wines is strongly conditioned by the timing of the harvest. When red wine is made in the Rioja, wineproducers wait until the grape is completely ripe. Being a marginal area the red grape takes a long time in forming all the colour necessary in its skin. This does not occur in Aragón or Castilla where the grapes form an intense red colour before the harvest.

On the other hand, when white wine is made, one can opt for bringing the harvest forward or putting it back. In both cases, the wine will be white, but with the early harvest it will be pale, acid, fresh, fruity and with low alcohol.

By delaying the harvest, the wine will be more insipid, smoother, with golden tones and hardly any fruity aromas.

We have to remember that white grapes are more delicate than the red varietes; they are susceptible to attack by moulds during ripening; this can spoil them, producing wines with an excessively golden colour. Therefore, in the Rioja, the harvest date can give us different types of white wines.

But the dual nature of white Rioja wines does not depend only on the harvest but basically on present-day tastes. One part of the market seeks Rioja white wines aged in oak for a few years - golden wines with a tendency towards an oxidised taste. It is a minority choice. A large group of consumers look for pale, fruity, young wines without a taste of oak. Market trends have forced bodegas to produce these wines. In complete agreement with this, we can also say that young, fruity wines are attained exclusively from the Viura grape, older, golden wines with Malvasia or white Garnacha. To sum up:

• Young, fresh white wines. Early harvest, Viura variety, fermentation at 22· C.
• Golden, ageable white wines. Late harvest, Garnacha or Malvasía varieties and fermentation at 25-30· C.

The white Viura variety is a grape which has important qualities for white Rioja wines, even for sparkling wines, while Malvasía and Garnacha have tewer possibilities due their tendency to produce wine with an oxidised, rancid taste.

Maderisation of wine is the oxidation of some white wines increasing the intensity of the colour until it is similar to wood. At the same time, the wine acquires a rough taste similar to the astringency of wood tannin.

There are also two methods of preparing white wines. One is the craft method and the other is industrial.

The craft method is based on the use of stone vats. When a wineproducer makes white wine, he harvests white grapes and places them whole in the vat, turning them over from time to time.

After a few hours he opens the tap or "canilla", situated in the lower part of the vat, through which a white must flows and ferments in underground vats of oak or cement.

Red grapes are thrown onto the pressed white grapes (the pressing is never severe); thereafter the white wine is made in the same way as the red. Some wineproducers have a small de-stemming machine through which the grapes pass, obtaining, after the tap is opened, a larger amount of must.

It is easy to understand that in vats with a higher capacity than 20,000 Kg, the wineproducer must turn the grapes over gently and, therefore, neither skins nor stems should be removed violently.

This results in very fine wines. The disadvantage in some areas near Najerilla, where the subsoil is so cool that grapes excessively poor in tannin are produced. This causes incorrect fermentation, and the disease known as "gras" or "graisse".

Industrial processing consists of working much larger amounts of grapes with a tendency towards continuous systems. The most important thing is to know the extent to which the grape juice should be worked in order to obtain wines which continue to be fresh and light-coloured.

The system with the most continuous process consists of the initial separation of the stem. Afterwards, the slightly injured grape goes on to a vibrating stainless-steel sieve which separates the "yema" (yolk) or "flor" (flower) must, which only requires gravity separation. The partially-drained solid mass goes on to a continuous press which exerts little pressure, separating more must. The pasty mass now goes on to a continuous horizontal press which separates three types of liquid depending on the pressure, the final liquid being unsuitable for wine-making.

There is a non-continuous system which gives high quality; it is based on a system of wooden cages. The pressed grapes are transferred to cement containers which are lined internally with cages made of wooden boards.

The must drains for some hours and the thick substance which remains is emptied into "horizontal presses". These are horizontal cylindrical cages, the bottoms of which are joined mechanically, squeezing out the liquid. These liquids are separated and are of different quality. They are white grape musts and are still cloudy. If they are left to ferment with this cloudy appearance, the wine becomes rough.

The cleaner the white grape must, the better the wine obtained. To clean the must, deposit-removing operations are carried out. The must is placed in vats for one day. During this time the solid materials that make the must cloudy precipitate. Separation is made by pumping the clean must and transferring it to another container where it ferments. This is called the "debourbage" or racking operation.