Originally Posted by Kauai_Kahuna
I am always tempted to do this, but I also like to keep my LHBS in operation since a buddy bought it. I do wash and store yeast but brewing different styles with different yeast I can go many months before I want to use something stored.
How long do yeast banks last in your standard household freezer?
I am thinking I would also need a stir plate to step up the cultures, etc.
Yes you do need a stir plate.
When I store them in distilled water it is at room temperature and from what I read you can store them in this fashion for 1 year or longer. I don't have personal experience with this as I just recently started but this information is coming from multiple sites. If you store them on slants (agar in a test tube) I think you need to reculture every 3-4 months. This means you make more agar slants and innoculate (transfer yeast) onto the new slant. Kind of like transferring the yeast to a new and better home.
I was not interested in reculturing this often and if a year goes by for one of my yeast banks I can always plate it on wort agar, let it sit for 2-3 days and bank it again in more sterile distilled water. This wouldn't be any more work than reculturing a slant except I can do it less often.
The down side to using sterile distilled water storage is that you are dealing with less yeast typically. So when it's time to revive a handful of them to make beer you need to be more careful with sterile technique. But I have not had problems and I don't go crazy with sterile technique. Below is a list of supplies that are necessary for sterile distilled water storage although additional supplies are nice to have.
-Pyrex flasks or equivalent for making starters (I would suggest, 100ml, 500ml, 1000ml and 2000ml)
-Magnetic stir bars
-Torch, alcohol lamp, bunsen burner (any)
-petri plates or small pyrex plates for wort agar
-Dry Malt extract (to make wort agar for yeast to grow on and starters)
-Agar or gelatin (to turn wort agar solid)
-Innoculating loop (can be bought off ebay or other sources)
-Rubbing Alcohol (to sanitize your working area)
-Small 8-10ml vials for storage (I have a great source for very cheap if anyone is interested)
-Distilled water (can get from walmart or wherever)
-Pressure cooker (allows you to sterilize including killing spores by going up to 250F.)
Seems like a lot of equipment but some people may already have most of it for making starters already. Also, a lot of this equipment can be obtained rather cheaply or a diy solution can be thought up.