Mr.Malty, Starter size & yeast viability:

[Hop Bomb]

Since most of the clubs are brewing for the barrel soon there will be a lot of starters being made. Ive got a few questions & im sure others have too.

Most of the barrel brews are going to be 1.090 -1.100 OG range. The best before dates on HBC white labs vials are 09 May 2013 meaning their manufacture date
is 09 Feb 2013.  This gives a yeast viability of 48%. (see below)



So going off this mr.malty calculation is it true that I need 2 new vials in a 2.79 litre starter? 

If I was making a starter from a slant how does the process differ? A slant has much much less yeast in it than a fresh vile.


Thanks in advance. (il buy that yeast book soon I promise)

[Dr Jacoby]

That looks about right to me for the White Labs vials. If you decide to use slants you'll need to go through the following steps:

1. Prepare about 100-250ml of 1.030-40 wort.
2. Swish some of this in your vial to remove the yeast from the agar agar.
3. Add this to the rest of the wort and culture up the yeast for about 24hrs.
4. Step up the starter to a one litre quantity for another day or two (at 1.030-40)
5. Step up the starter one last time to the desire quantity, in this case at least 3 litres I'd guess (at 1.030-40)

Strictly speaking the last step is not ideal, since it is usually best to step up the quantity by a factor of 10, but that doesn't matter all that much since you are not looking to grow the maximum amount of yeast; you are looking to grow a sufficient amount, which this method should give you.

Another option is to brew a mid strength ale with the yeast you plan to use for the imperial stout (or whatever strong beer you want to age in the barrel) and pitch the strong wort on to the resulting yeast cake. This is a much less precise method and you will definitely over pitch, but since you won't be using the same yeast again (after torturing it in an 8 - 10% ABV black thick syrupy nightmare), it doesn't really matter if it takes a beating. But if you are worried about over-pitching you could just scoop some of the yeast cake out of the mid strength ale trub.

[Hop Bomb]

Perfect! Thanks for such a detailed reply.

[Hop Bomb]

I just got some slants ready there on my lunch break. The vials are in the fridge now so hopefully they set. My first time ever using a pressure cooker (and first time slanting).
I was terrified it was going to explode (all I could think of was Boston Bombing).  Thanks to Stout Fellow for the how to blog post. http://stoutfellow.wordpress.com/2012/05/23/yeast-ranching-storing-yeast-on-slants/