An Analysis of Novel Yeasts and their Brewing Potential
Abstract
Within the brewing community, there is always a race to discover new ways to brew beers and create new flavor and smell profiles. While most beers are brewed using one of a handful of domesticated yeast strains also known as pitching yeasts, finding “wild” yeasts is one way to change fermentation products. To discover new yeasts that might be appropriate for brewing, local fruits were harvested from campus trees. After conducting several identification experiments, they were confirmed as yeasts and testing has now begun to identify the potential these species have for the brewing industry. To identify the ideal conditions each grow at, we are evaluating the growth rates at different temperatures, ethanol concentrations, and pH levels. These standards are all monitored and strictly controlled in the brewing industry since they all lead to specific changes in the fermentation product. Growth temperature data was collected for 20, 25, 30 degrees Celsius and the optical density of the liquid culture was monitored over five days. The 25 degree Celsius curve was then used as the condition for the next two tests. Tolerance for ethanol was tested by using varying concentrations of ethanol added (3, 5 and 7 percent concentration) to the YPD media and measuring the optical density over five days. Tolerance to different pHs was tested by adding varying amounts of NaOH and HCl to the YPD media to maintain a pH of 3, 4 and 5 and optical density was measured over five days. Data collection was standardized by controlling for the media absorbance, initial concentration of cells, and spectrometer standardization protocol. The ethanol and pH experiments both test the tolerance of the three species, and the ideal conditions will be determined by final optical density after the five day period. These three tests will help determine the potential each of the three species have for the brewing industry.
An Analysis of Novel Yeasts and their Brewing Potential
CNS E103
Within the brewing community, there is always a race to discover new ways to brew beers and create new flavor and smell profiles. While most beers are brewed using one of a handful of domesticated yeast strains also known as pitching yeasts, finding “wild” yeasts is one way to change fermentation products. To discover new yeasts that might be appropriate for brewing, local fruits were harvested from campus trees. After conducting several identification experiments, they were confirmed as yeasts and testing has now begun to identify the potential these species have for the brewing industry. To identify the ideal conditions each grow at, we are evaluating the growth rates at different temperatures, ethanol concentrations, and pH levels. These standards are all monitored and strictly controlled in the brewing industry since they all lead to specific changes in the fermentation product. Growth temperature data was collected for 20, 25, 30 degrees Celsius and the optical density of the liquid culture was monitored over five days. The 25 degree Celsius curve was then used as the condition for the next two tests. Tolerance for ethanol was tested by using varying concentrations of ethanol added (3, 5 and 7 percent concentration) to the YPD media and measuring the optical density over five days. Tolerance to different pHs was tested by adding varying amounts of NaOH and HCl to the YPD media to maintain a pH of 3, 4 and 5 and optical density was measured over five days. Data collection was standardized by controlling for the media absorbance, initial concentration of cells, and spectrometer standardization protocol. The ethanol and pH experiments both test the tolerance of the three species, and the ideal conditions will be determined by final optical density after the five day period. These three tests will help determine the potential each of the three species have for the brewing industry.