I wanted to propogate some yeast and decided to implement my working knowledge of microbes.
After growing up a 300mL culture of WLP008 east coast ale yeast, I spun down the cells at 4000rpm (yes, in a centrifuge) for 15 minutes and then discarded the spent media. I added 30mL of gylcerol and filled the volume to 300ml with sodium phosphate buffer (for a 10% solution of glycerol) and then I aliquoted 50 mL portions into sterile screw top tubes.
Glycerol is certainly an available carbon source for yeast and I am assuming it will be broken down by the organisms when they finally make it into the wort. Alternative preservatives (that would allow me to freeze the yeast) include EDTA and glycerine. Any suggestions on which if any would be better than glycerol. I just used it because it is standard...
Would calcium chloride buffer be a better alternative to sodium phosphate? I'm not quite sure how it will affect the quality of the beer when I reconstitute it.
Thoughts? Comments? Anyone want some yeast?
After growing up a 300mL culture of WLP008 east coast ale yeast, I spun down the cells at 4000rpm (yes, in a centrifuge) for 15 minutes and then discarded the spent media. I added 30mL of gylcerol and filled the volume to 300ml with sodium phosphate buffer (for a 10% solution of glycerol) and then I aliquoted 50 mL portions into sterile screw top tubes.
Glycerol is certainly an available carbon source for yeast and I am assuming it will be broken down by the organisms when they finally make it into the wort. Alternative preservatives (that would allow me to freeze the yeast) include EDTA and glycerine. Any suggestions on which if any would be better than glycerol. I just used it because it is standard...
Would calcium chloride buffer be a better alternative to sodium phosphate? I'm not quite sure how it will affect the quality of the beer when I reconstitute it.
Thoughts? Comments? Anyone want some yeast?