Pure Culture Fermentation

Research using eight Brettanomyces strains was conducted to observe the effects of two variables during pure culture fermentation. The first study focused on observing fermentation performance and the compounds produced with three different pitching rates. Fermentations were conducted using standard wort and a primary pitching rate of 12×106 cells/ml. The impact of pitching rate on fermentation performance was then examined using two additional pitching rates (6×106 and 18×106 cells/ml) and comparing the relative quantities of compounds produced during each. Determining adequate pitching rates with brewers yeasts is an important factor in creating consistent, quality beer with changes to the initial cell concentration at the on-set of fermentation often having noticeable effects on the over-all fermentation performance. A second study involved dosing wort with varying levels of lactic acid prior to fermentation. This study was performed using lactic acid at concentration of 100, 500, 1,000, and 3,000 mg/l to observe the effects initial wort pH had on fermentation performance and the compounds produced. The following links detail the methods used to conduct the pure culture fermentation studies along with the subsequent results and discussion.

Pure Culture Fermentation Methods

Methods used to observe fermentation performance during pure culture fermentation.

Impact of Pitching Rate on Pure Culture Fermentation

Results obtained from observing the impact that pitching rate had on fermentation performance during pure culture fermentation.

Impact of Initial Lactic Acid Concentration on Pure Culture Fermentation

Results obtained from observing the impact that initial lactic acid concentration had on fermentation performance during pure culture fermentation.

Pure Culture Fermentation Discussion

Discussion of the results obtained and their importance to Brettanomyces spp. pure culture fermentation.