Building a Starter from a Small Yeast Sample

[helmet]

I made a WLP002 starter a while ago and saved 100ml of it in the fridge. Can I build this up to a functional starter for a 5 gallon batch or should I just chuck it?

[irish_goat]

How old is it?

[helmet]

About 2 months.

[irish_goat]

Should be fine. Some people on here use yeast slants, which are comparatively tiny amounts of yeast compared to what you have there. Start with a small starter for the first 24 hours and then build it up as you would normally and you'll be grand.

[helmet]

Great stuff, waste not want not!
When you say start with a small start what kind of size?

[irish_goat]

I'd say about 100-200ml of wort at 1.040 OG.

[helmet]

Brilliant, thanks a million.

[Greg2013]

Good to know as i have similiar situation here with WLP029. Can you also grow up a starter with dry yeast ?

[tipp brewer]

No need for a starter from dry yeast from what I've read as the dried yeast have their cell walls reinforced/strengthened - so are healthier and stronger though maybe not as tasty (i.e. the front row of the scrum), this isn't the case with liquid yeasts as they are more sensitive souls but do have more flair (You guessed it the back division) - read that somewhere sorry there is some science behind it.
If you're asking could you make 2 starters from the same packet of dried yeast, I don't see why not though I'm no expert, I guess it would be no different from harvesting your yeast from your fermentor, but I guess you should give it some time before pitching to improve the yeast cell count. 
I've never made a starter and just done a brew with liquid yeast for the first time - Again I didn't make a starter and just chucked it in from the vial, it was out of date so I really should have made the starter but didn't think of it till the beginning of brew day - It's now 24 hours with no sign of fermentation but I have read it can take 36 hours + to get going so I'm far from a yeast expert.