Yeast Breeding

I'm a cheapskate, so I was wondering:

How easy would it be for me to save a little yeast from each strain that I buy and propagate it myself so as to keep a constant stock of several strains and possibly not have to buy yeast again? How long would these keep?

You can definately go this route. There is quite a bit of discussion on how long yeast should be propagated, but I've heard of people going at least 5 generations. Start with this thread https://www.homebrewtalk.com/f13/yeast-washing-illustrated-41768/ for more information.

Thanks McKBrew!

Or you can save some of the original yeast out of the tube/smack pack on a slant:
Yeast Slants - Home Brewing Wiki
Yeast Slant FAQ by Mike Sims

I use slants as I "save" one fermentation of yeast mutations. The general ROT is to not use yeast after 5 -6 fermentations as the yeast will have sufficiently mutated as to change its fermentation behavior. If you harvest after the first fermentation and culture starters off of that, you're probably fine.

I've been doing slants from any liquid culture I purchase, but recently have started experimenting with storing yeast cells in distilled, room-temp water based on an old Brewing Techniques article.

The pages of the article have been scanned and torrented for research and educational purposes.

I found FlyGuy's frozen yeast bank to be pretty amazing too, and there is a great step by step write up...

Frozen Yeast Bank

fratermus and Fly Guy, please keep us all up to date on the success and life of your storage techniques. I've found the slants to be reasonable to prepare, store and propogate, but only have a scant 6 month history myself.

Maybe we'll have to figure out how to store our yeast in amber for some really long shelf lives:
The Daily News Online > This Day > Historic beer has prehistoric roots

So far, I have generally been happy with frozen yeast banking. I haven't done slants myself, but that was a conscious decision based on doing the same process in university (freezing is more straightforward with somewhat less to go wrong, IMO).

I wish I had a better sample size and better records, but it appears that freezing yeast doesn't work equally well with all yeasts. For example, German hefeweizen yeasts don't do well in the freezer (but they are notoriously difficult to maintain using slants, too). On the other hand, American Ale yeast seems indestructible (that's a clear winner for freezing).

Overall, I think either method has its own pros and cons, and you simply have to learn what suits you best. None are a clear winner in every circumstance.

R.E yeast washing, apparently it has fallen out of favor, I harvest my yeast cakes, simple process swill up the cake with a little beer and bottle it in a PET and refrigerate for a night.
Next day the beer is on top and the yeast under. Pour off most of the beer, will up the rest and bottle in a 330ml bottle. Obviously sterilize everything. When i want to use this yeast i take it out of the fridge a couple of hours b4 pitching. 100-200mls of this solution is heaps....
BEWARE, i have had some of these bottles spout beer when opened as the yeast is still active in the beer solution. If you are concerned with this pour off some yeast and add water instead. I prefer beer solution as it is likely to keep the yeast alive longer.