Need quick help with Wyeast Propagator Pack

[CarlosHernandez]

Thinking about brewing this Friday and I need WLP007. Only problem is, I can only get Propagator Wyeast 1098 (25 billion cells) locally. Never used Wyeast packs with such low cell counts before. I thinking about buying 2 packs (50 billion cells) and making a starter.

How big of a starter do I need? Tried using Mr Malty but I think calculations are based on using a 100,000 billion cell count vial.
Should I "step" the starter? and if so, how do you properly step a starter? Heard of the term "stepping" plenty, but don't really know the precise way of doing it.

I appreciate any help, gotta order by tomorrow.
Thanks!

[jm]

Thinking about brewing this Friday and I need WLP007. Only problem is, I can only get Propagator Wyeast 1098 (25 billion cells) locally. Never used Wyeast packs with such low cell counts before. I thinking about buying 2 packs (50 billion cells) and making a starter.

How big of a starter do I need? Tried using Mr Malty but I think calculations are based on using a 100,000 billion cell count vial.

In the pitching rate calculator you can set the viability to 25% (25b cells) or 50% (50b cells) to get an accurate volume for your starter; i.e. 100b cells = 100% viability.

[Quin]

To elaborate, punch in the manf. date for the package. Say your viability is 70%, you would then manually change the percentage to 25 x 0.7 = 17.5%

Reduce the batch size until only 100 billion cells are needed and slide the dial so that only 1 vial is used. This will give you the starter size to get 100 billion cells. You can then change the viability to 100%, enter your beer's gravity and volume, and see what the next step is.