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Yeast: Difference between revisions
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===Starters for liquid yeast=== | ===Starters for liquid yeast=== | ||
Yeast produce membrane lipids only when grown aerobically. In the initial growth phase, proper oxygen management leads to proper production and storage of sterols in the yeast cell, which can be shared with subsequent daughter cells. It is possible to increase yeast ethanol tolerance by promoting synthesis of sterols, by adding oxygen (air) in the starter and during fermentation. Yeast lees deplete the oxygen content and can impact the redox potential and formation of VSCs.<ref name="Zoecklein"/> | Yeast produce membrane lipids only when grown aerobically. In the initial growth phase, proper oxygen management leads to proper production and storage of sterols in the yeast cell, which can be shared with subsequent daughter cells. It is possible to increase yeast ethanol tolerance by promoting synthesis of sterols, by adding oxygen (air) in the starter and during fermentation. Yeast lees deplete the oxygen content and can impact the redox potential and formation of VSCs.<ref name="Zoecklein">Zoecklein B. [https://www.apps.fst.vt.edu/extension/enology/EN/133.html Enology notes #133.] Wine/Enology Grape Chemistry Group at Virginia Tech. Published 2007. Accessed 2020.</ref> | ||
While oxidative stress is known to occur, is it significantly less that stress from carbon dioxide. High amounts of foam means that insufficient oxygen delivery is occurring.<ref>https://www.mbaa.com/publications/tq/tqPastIssues/2005/Abstracts/TQ-42-0128.htm</ref> | While oxidative stress is known to occur, is it significantly less that stress from carbon dioxide. High amounts of foam means that insufficient oxygen delivery is occurring.<ref>https://www.mbaa.com/publications/tq/tqPastIssues/2005/Abstracts/TQ-42-0128.htm</ref> | ||