The ‘Criaderas and Solera’ System in Sherry Wines: Biological Aging, Flor Yeast Dynamics, Industrial Applications and Emerging Challenges—A Review

The Criaderas and Solera system represents one of the most sophisticated aging methodologies in winemaking, producing distinctive Sherry wines through dynamic blending and biological aging processes. This traditional Spanish system, combined with the unique metabolic activities of flor yeast (<i>Saccharomyces cerevisiae</i>), creates wines of exceptional complexity and consistency. This comprehensive review synthesizes current literature on the Criaderas and Solera system, focusing on biological aging mechanisms, flor yeast dynamics, industrial applications, and contemporary challenges. Recent advances in genomic, proteomic and metabolomic studies of flor yeasts have been analyzed, alongside modern analytical approaches to the characterization of Sherry wine. The Criaderas and Solera system enables consistent wine quality through fractional blending across multiple aging levels. Flor yeasts exhibit specialized metabolic adaptations, including enhanced ethanol oxidation capacity, biofilm formation abilities, and stress resistance mechanisms. Modern applications extend beyond traditional winemaking to include biotechnological uses, immobilization techniques, and sustainable production methods. Current challenges include climate change impacts, maintaining genetic diversity, adapting to new technologies and meeting evolving consumer preferences. The integration of traditional knowledge with modern biotechnology offers promising opportunities for optimizing Sherry production. Understanding flor yeast ecology and metabolic pathways provides insights for developing innovative applications while preserving the authenticity of this centuries-old winemaking tradition.