Carmen González

By María Jesús Callejo, Carmen González and Antonio Morata

Bottle fermented and brewed beers are reaching more recognition in present days due to their high sensory complexity. These beers normally are produced by an initial tank fermentation to metabolize the sugars obtaining the typical alcoholic degree, and later the foam and CO2 pressure is produced by subsequent bottle fermentation. The sensory profile is improved by the formation of some fermentative volatiles, but also by the ageing on lees, because beers are brewed during several months with the yeast cells that performed the fermentation. The use of non-Saccharomyces yeast is a trending topic in many fermentative food industries (wines, beer, bread, etc.). They open new possibilities to modulate flavor and other sensory properties during fermentation and biological ageing. This chapter review the effect of some non-Saccharomyces yeasts such as Schizosaccharomyces pombe, Torulaspora delbrueckii, Lachancea thermotolerans, Saccharomycodes ludwigii, and Brettanomyces bruxellensis in the bottle fermentation and brewing of beers analyzing their metabolic specificities and sensory contribution on beer taste.

Part of the book: Brewing Technology

By Antonio Morata, Iris Loira, Juan Manuel del Fresno, Carlos Escott, María Antonia Bañuelos, Wendu Tesfaye, Carmen González, Felipe Palomero and Jose Antonio Suárez Lepe

Trends in wine consumption are continuously changing. The latest in style is fresh wine with moderate alcohol content, high acidity, and primary aromas reminiscent of grapes, whereas certain fermentative volatiles may also influence the freshness of the wine. In addition, the effects of climate change on the composition of the grapes (high sugar content and low acidity) are adverse for the quality of the wine, also considering the microbiological stability. Herein, different strategies aiming at improving wine freshness are presented, and their performance in winemaking is discussed: among them, the addition of organic acids able to inhibit malolactic fermentation such as fumaric acid; the use of acidifying yeasts for alcoholic fermentation, such as Lachancea thermotolerans; and the selection of non-Saccharomyces yeasts with β-glucosidase activity in order to release terpene glycosides present in the must.

Part of the book: Advances in Grape and Wine Biotechnology

By María Jesús Callejo, Wendu Tesfaye, María Carmen González and Antonio Morata

During the twentieth century, the consolidation of large multi-national beer companies and the homogenization of the specified beer types have led to a considerable growth in the beer industry. However, the growing demand by consumers of a single and distinctive product, with a higher quality and better sensory complexity, is allowing for a new resurgence of craft beer segment in recent years. This chapter reviews some different alternatives of innovation in the craft brewing process: from the bottle fermented beers with non-Saccharomyces yeast species, to the use of special malts or specific adjuncts, hop varieties, water quality, etc. All of them open a lot of new possibilities to modulate flavor and other sensory properties of beer, reaching also new consumers looking for a specific story in one of the oldest fermented beverages.

Part of the book: New Advances on Fermentation Processes

By Antonio Morata, Iris Loira, Buenaventura Guamis, Javier Raso, Juan Manuel del Fresno, Carlos Escott, María Antonia Bañuelos, Ignacio Álvarez, Wendu Tesfaye, Carmen González and Jose Antonio Suárez-Lepe

This chapter reviews the main non-thermal technologies with application in enology and their impact in: the extraction of phenolic compounds from grapes, the elimination of indigenous microorganisms, and the subsequent effect in SO2 reduction. The technologies are physical processes with null or low repercussion in temperature and therefore gentle with sensory quality of grapes. High hydrostatic pressure (HHP), ultra high pressure homogenization (UHPH), pulsed electric fields (PEFs), electron-beam irradiation (eBeam), ultrasound (US), and pulsed light (PL) have interesting advantages and some drawbacks that are extensively reviewed highlighting the potential applications in current technology.

Part of the book: Chemistry and Biochemistry of Winemaking, Wine Stabilization and Aging

By Antonio Morata, Carlos Escott, Iris Loira, Juan Manuel Del Fresno, Cristian Vaquero, María Antonia Bañuelos, Felipe Palomero, Carmen López and Carmen González

Lachancea thermotolerans is a yeast species that works as a powerful bio tool capable of metabolizing grape sugars into lactic acid via lactate dehydrogenase enzymes. The enological impact is an increase in total acidity and a decrease in pH levels (sometimes >0.5 pH units) with a concomitant slight reduction in alcohol (0.2–0.4% vol.), which helps balance freshness in wines from warm areas. In addition, higher levels of molecular SO2 are favored, which helps to decrease SO2 total content and achieve better antioxidant and antimicrobial performance. The simultaneous use with some apiculate yeast species of the genus Hanseniaspora helps to improve the aromatic profile through the production of acetyl esters and, in some cases, terpenes, which makes the wine aroma more complex, enhancing floral and fruity scents and making more complex and fresh wines. Furthermore, many species of Hanseniaspora increase the structure of wines, thus improving their body and palatability. Ternary fermentations with Lachancea thermotolerans and Hanseniaspora spp. sequentially followed by Saccharomyces cerevisiae are a useful bio tool for producing fresher wines from neutral varieties in warm areas.

Part of the book: Grapes and Wine

By Antonio Morata, Carlos Escott, Juan Manuel del Fresno, Buenaventura Guamis, Iris Loira, María Antonia Bañuelos, Carmen López, Felipe Palomero and Carmen González

Ultra-High Pressure Homogenization (UHPH) is an emerging non-thermal technology that uses continuous pumping at 200–600 MPa (generally 300), and then the fluid is depressurized against a special valve made with highly resistant alleys and coated with diamond powder. The UHPH process is able to sterilize grape juice or whatever food fluid and at the same time is extremely efficient in inactivating oxidative enzymes. The total elimination of wild microorganisms in grape juice allows the perfect implantation of the selected Saccharomyces cerevisiae starter facilitating the expression of particular metabolic profiles or the expression of specific extracellular activities. Furthermore, the use of complex emerging biotechnologies such as the use of co-inoculations with S. cerevisiae and lactic acid bacteria to perform simultaneously alcoholic and malolactic fermentations works much better if the initial juice has a very low load of wild microorganisms. Additionally, the development of spoilage processes by wild microorganisms that can remain in the wine after fermentation is practically impossible when the initial juice is treated by UHPH. Thus, UHPH helps to obtain wines more stable from a microbiological perspective and therefore safer and more hygienic.

Part of the book: New Advances in Saccharomyces