Project Updates

Over the past couple of weeks I have been in talking with Greg Doss the QC manager at Wyeast labs and they will be helping out the Brettanomyces Masters Project by shipping over slopes of B. lambicus (5526), B. bruxellensis (5112), and the VSS for April to June B. claussenii (5151). Thanks to Greg for his help and I look forward to receiving the cultures once they are shipped and clear customs!

As the project continues, I now have five pure culture strains of Brettanomyces and have started observing cell growth phases during batch culture propagation. All five strains were seperatly inoculated into 250 ml flasks containing 100 ml of wort solution taken from the standard wort produced and being used throughout the entire project. The flasks containing the wort were loop inoculated with cells from the top of a single colony grown on MYPG agar plates. These five strains were then propagated up over a 16 day period and at that time the 100 ml yeast slurry was pitched into 500 ml of new sterile wort solution and grown in a 1.5 litre flask. From here I will again be taking daily cell counts to observe the growth phases for each strain during propagation in order to observe when is best to pitch for fermentation and get a better idea of the ideal propagation methods to be used with Brettanomyces yeast species. Watch for the results in the future and the possibility of further experiments which look to further maximize cell growth during propagation.

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~ by Chad on April 12, 2009.

2 Responses to “Project Updates”

  1. by placing them in a 28C incubator, wont you select for cells that prefer the warmer temps, whereas most beers are fermented much cooler

    I would think doing this could significantly effect the fermentation

  2. The temperatures beers are fermented at are different from the range of temperatures cells funtion and grow at. In most brewing text it states how Saccharomyces sp. cells will culture faster at higher temperatures and cells will sustain viability up past 30 degrees to nearly as high as 40 degrees C if I’m remember correctly. Culturing Brettanaomyces below 25 degrees C is increadibly slow and both Wyeast and White Labs have advised cultureing at 25+ degrees C. I’m looking into the effects of propagation on fermentations now and will be adjusting the temperature to view if it affects fermentation.

    Also remember that wine fermentation take place as high as 30 degrees C sometimes. So the thought of temperature is something not to be so concerned with more the behavior of the yeast which may not be the same as “Brewers” yeast so these conditions are not an absolute and only a guidlines which brewers follow.

    Another note is that even comercial lager companies culture thier yeasts at around 25 degrees C before pitching into fermentation that will ferment at 10-12 degrees C. So by culturing at a higher temperature I’m not selecting for cells which function better at a higher temperature I’m giving the cells a favorable environment before they go into an un-favorable environemnt “fermentation”.

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