Ripening

Ripening is the culmination of the fruit on the vine. It begins in August, after the "envero" or "veraison" and involves a series of gradual processes which start with the green grape and finish with the ripe grape; which is picked and goes on to thefermentation process.

It is an over simplification to say that when the grape ripens its sugar content increases. This is clear, but is only one aspect of the many which can be observed.

We must distinguish between physical aspects such as the variation in the size of the grape, variation in its hardness and weight, and chemical aspects such as the increase in sugar, the loss of acidity and oxidability.

For Rioja wine, the ripening of the grapes involves a series of complex changes in the grape from August to September.

Increases: The sugar content increases in the grape, which afterwards will produce the alcohol. The weight and size of the grape increases as well as the oxidability of the must, not forgetting the colour of the grape skin in the case of red varieties.

Decreases: The acid content goes down, and with it the acid taste as well as the hardness of the skin.

We can understand that if we bring the grape harvest forward two weeks, we will obtain a wine with a lower alcohol content, less colour and more acidity than in the case of a late harvest.

The data on these charts has been taken from the Rioja Alta (Cenicero, Briones, Haro and Villalba). The typical date of the grape-harvest of this area is the festival of Santa Teresa. A date which indicates, year after year, an acceptable level of ripeness for the great wines of the Rioja.