The objective of the work is twofold: to identify and isolate fermentation yeasts and to help determine the chemical characteristics of Bizkaia txakoli. For this purpose, the volatile components and their evolution in the process will be analyzed. Yeasts may be selected based on their fermentation characteristics.
At Zalla Station, samples of a single variety of grapes will be taken from the adult grape, the must before and after the sulfitate, the turbulent fermentation and the end of fermentation. Volatile components will be determined by gas chromatography. In the arrival of the grapes and in the usual process of making txakoli, the corresponding yeasts will be taxonomically isolated and identified, at least, in 1996 and 1997. Oenological evaluation of Sacharomyces cervisae strains.
Txakoli is a wine from Euskal Herria that has more and more social and economic importance. The methods of making txakoli and its chemical components have been little analyzed to date.
The Designation of Origin Bizkaiko Txakolina was obtained in 1994 (BOPV 94-VI-14) and for this purpose a study and report of enological parameters was carried out. The project, currently funded by the UPV/EHU, aims "The determination of the main volatile components".
In the txakoli industry there are many systems and techniques, but many are inadequate or obsolete. However, the quality of txakoli depends mainly on the quality of the initial must, the technological conditions of the winery and the participating yeast strains. Grape varieties, edafolophy and climate are related to the composition of the must. Yeast strains adapted to these ecological conditions are also developed. Isolating these natural strains and using them to ferment our musts is an opportunity to avoid the uniformization of wines.
Selected fermenting yeasts and Active Dry Yeasts (L.L.A.) are currently used are called. However, these commercial yeasts have been obtained far from the territory of our Denomination of Origin, which makes the production of wine in the molt today too homogeneous.
The main objective of this study is the analysis and selection of txakoli yeasts and their relationship with aromatic composition through the analysis of volatile components.
The work objectives are: