Ive just stated to delve into the world of yeast management. So far Ive washed yeast out of a primary and am storing it in the fridge for a brew in a few weeks. Also, mostly as an experiment, Ive mixed some with 10%glycerin to freeze. I havent used any of my saved yeast in a brew yet, so well see how that goes in the future (fingers crossed!). For now Im contemplating if/how to go about getting into proper yeast banking/ranching.
My question is about and master and working stocks (using agar slants). Basically Im wondering what precisely theses are, and how they work in practice? I recall reading somewhere that its common practice to maintain a master stock that is only used for re-propagating masters and inoculating the working stocks. The working stocks are then only used for inoculating your starters. Is that the correct workflow?
If so, is a master stock normally just one vial of each strain? or should you keep two or three to reduce risk of losing the strain?
How many vials of the working stock? I assume this probably depends on how often you use the strain within the life of the slant? What do people here use personally?
When propagating the master, do you simply inoculate a new slant and then call it a master, or should you go thru the intermediate step of streaking a plate? (I assume the only reason to streak a plate is to ensure youre only propagating pure cultures?)
What about using frozen slurries as youre master? Is there a problem in thawing and re-freezing every time you want to inoculate new working slants?
Lots of questions... I know! Looking forward to feedback from the amazing wealth of knowledge in this community!
Cheers!
My question is about and master and working stocks (using agar slants). Basically Im wondering what precisely theses are, and how they work in practice? I recall reading somewhere that its common practice to maintain a master stock that is only used for re-propagating masters and inoculating the working stocks. The working stocks are then only used for inoculating your starters. Is that the correct workflow?
If so, is a master stock normally just one vial of each strain? or should you keep two or three to reduce risk of losing the strain?
How many vials of the working stock? I assume this probably depends on how often you use the strain within the life of the slant? What do people here use personally?
When propagating the master, do you simply inoculate a new slant and then call it a master, or should you go thru the intermediate step of streaking a plate? (I assume the only reason to streak a plate is to ensure youre only propagating pure cultures?)
What about using frozen slurries as youre master? Is there a problem in thawing and re-freezing every time you want to inoculate new working slants?
Lots of questions... I know! Looking forward to feedback from the amazing wealth of knowledge in this community!
Cheers!