Yeast Harvesting without washing???

[evillegas]

So I made a 5 gal batch of pale ale a few weeks ago, I harvested the yeast cake from my fermenting bucket, leaving behind most of the trub. I added some un-fermented wort I had stored in the fridge (from the same batch, just the last runnings from the mash tun that I boiled for an hour separately with no hops).

I put this in a sanitized 2 liter plastic soda bottle, and stored it in the fridge. Is this yeast viable? will it still work for another batch of the same pale ale? how much should I use on another 5 gal batch? the whole thing?

Thanks for your input, cooking maybe this sunday and want to know if I can use this yeast or just get a new vial.

Thanks again.

Ed.

[brewfun]

The thing to consider is your sanitation. If it's pretty good, then you're probably fine reusing that yeast.

[Slobrew]

I always do a yeast starter prior to using my harvested yeast. If it gets going in the starter then I'm sure it will be ok with the wort. I also keep a packet of dry yeast on hand just in case the harvested yeast flops. So far I have not needed the dry yeast.

[Scott Ickes]

I always do a yeast starter prior to using my harvested yeast. If it gets going in the starter then I'm sure it will be ok with the wort. I also keep a packet of dry yeast on hand just in case the harvested yeast flops. So far I have not needed the dry yeast.

I also always make a starter for my harvested yeast, for the reason Slowbrew stated and for one additional reason.  I even do it as a stepped starter, if my harvested yeast is old.

The reason I do a stepped starter is:
If you let the starter go all the way out, then chill it down to let it separate, you'll have layers.  You can pour off the beer from the top layer, then pour about 75% of the yeast slurry off into a sanitized mason jar.  This leaves behind most of the dead yeast cells from your slurry, as most of them will be at the bottom of the slurry.

You then clean and sanitize your flask and pour the good yeast from your mason jar back in and do your next step up of your yeast. 

I like leaving as much of the dead yeast behind as possible.  I use yeast nutrient when brewing and in my starters, so the yeast have all they need.