Criadera system

Sherry wines are obtained from young wines, carefully selected soon after completing fermentation. These are typically fortified by adding vinous alcohol until they reach an alcohol content of 15-15.5°. They are subsequently transferred to oak barrels before being aged. In most sherries, wine aging occurs in the so-called solera and criaderas system under the flor film of yeast. Once alcoholic fermentation is finished, races of Saccharomyces cerevisiae that can grow on the surface of the wine switch from fermentative to oxidative (respiratory) metabolism. They spontaneously form a biofilm called flor on the wine surface. 

Fino wine, which is the best known type of biologically aged wine, is obtained by using the criaderas and solera system, which essentially involves the periodic homogenization of wines of different age. This process is complex and expensive, but produces wines of uniform quality over time. Also, it makes the vintage notion meaningless. 

Recently, the effect of rocto in the different scales of a criadera and solera system and that on wine uniformity during the aging process have been examined (Berlanga et al. 2004a, 2004b). 

Recently, Berlanga et al. (2004b), using discriminant analysis, established differences among wine samples from the same criaderas y solera system. 

Metabolite concentrations in wine depend on the particular aging conditions, number of rows in the criaderas and solera system, number of rocios and volume extracted for bottles per year, ratio area of the flor film to volume of wine, climatic conditions of the cellar (temperature and relative humidity) and alcoholic concentration, in addition to the particular flor yeasts present. Below are described the most common changes observed during the biological aging of wine, whether related to yeast metabolism or otherwise. 

In Montilla-Mories and Jerez winemaking regions there are fundamentally three different types of white wines, namely flno, amontillado and oloroso, which are obtained by using the criaderas and solera system. 

Fig. 14.3. Solera system, showing the partial drawing off and redistribution of wine into the next lowest row of barrels of an older criadera stage. This operation was begun by removing 120 1 from barrels on the lowest level (or solera) for bottling...

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