Saved yeast. Use starter or pitch directly?
 

I washed and saved yeast (Wyeast 1072) from a pale-ale batch in a carboy. I got almost a quart of nice, tan-looking slurry. It had been in the carboy for three weeks from the brew day. I chilled the carboy for one day to settle it out for bottling.
Should I make a starter to use my yeast for two carboys (a rye beer next) or warm it up and pitch directly? I have heard this recommended both ways.

One more thing. Does anyone bottle directly into 1/2 gal. growlers? I have several of them with good caps.

As long as the slurry is pretty fresh, like yours seems, I pitch the slurry. Use the calculator at:
Www.mrmalty.com/calc/calc.html
And select the slurry tab for proper pitching rates.

I would not bottle condition in a growler. It has been done successfully but they have also exploded. Growlers aren't designed to hold that kind of pressure.

+1; if it's clean and healthy then pitch directly. do a search search for bottling in growlers you will find many warnings about them not being designed for pressure

Viability will be a function of ABV of the beer and the time between pitch and harvest.

http://woodlandbrew.blogspot.com/2013/01/abv-effects-on-yeast.html

What was the ABV level? Mr. Malty has been way off in my experience for predicting the number of viable cells in a slurry. Twenty times off last time I used it. A reasonable estimate for a saved slurry is 1 billion cells per ml.

For the story and real data see here:
http://woodlandbrew.blogspot.com/2012/11/counting-cells.html

This was one of my motivations for buying a microscope.

It was 22 days between pitch and harvest. My ABV calculates to about 5.1%. If 1 billion cells per ml is correct (thanks for that) I probably have 750-800 b. cells. Since a Wyeast "smack pack" contains about 100 billion cells, I should have plenty of yeast form my next 44litre +- brew.

It's never a bad idea to do a starter, worst case you reinvigorate your yeast. Is it worth it to chance a wasted batch?

Also that's enough yeast for a healthy pitch of 1 44 Litre batch with a starting gravity of 18 plato (1.074) , using 1 million cells/per degree plato/per ml.

22 days at 5.1%ABV will leave you at about 80% viability. If you want, I'll count your slurry for free. Send me a privet message and ill give you the details.

I've made a starter from a saved yeast cake, here is the link to the math I used which needed two yeast pitching sites. I ended up over pitching though, it's so hard to tell how much viable yeast is really in those cakes without a yeast count

http://www.homebrewtalk.com/f163/putting-washed-yeast-into-starter-295944/index2.html

Woodland Brew: Thanks for the input. I happened to see my brewing guru (the evil one that got me started in this obsessive compulsive hobby). He thought that I have a really nice batch of healthy yeast (nearly a quart) and could pitch directly without any problems. Somewhere I have a fairly high quality microscope that I could easily see yeast cells and probably bacteria, so I will look at that link you sent. Thanks.