Think I can be precise enough on my "calculated" pitch rate from a saved slurry that's been in the fridge for 5-6 months?
Here's the details:
-Thin slurry (WY 3068 - Weihenstephan Weizen) was harvest from Weizen batch (12.33 plato or 1.050) then put in 250ml jar in the fridge for future usage.
-Asked WY technicians about getting a good "banana" (isoamyl acetate) flavor. Reply is that pitch rate affect this aspect. Suggest 6 million cells/ml or a complete Activator pack. Also mentioned that "If you go above 12 million cells/ml, this flavor will not be very noticeable."
-Yesterday I got out of the fridge the jar of slurry and prepared (sterilized) a small (~750ml) starter to "wake up" the yeast. Let both the slurry jar and starter temperate and equalize for the night at ~21°C (70°F). The idea at this point is to verified the viability of the yeast and to harvest just the yeast cells in suspension to start up a new fresh starer again from ~500ml. I want to eliminate the dead cells and old trub.
-The slurry has already create a lot of pressure during the night. I crack open the jar when I got it out of the fridge so that was "new" pressure this morning. Again, this slurry was harvest on November 2009.
-I have to be somewhat accurate in my pitching rate to achieve something close to 6 million cells/ml and not getting too close or above 12 million cells/ml.
-WY technicians said that an Activator pack is about 90-100ml of thin slurry and that should be just what I want to get the flavor I want for a 20 liters batch.
Now the question... so I just need to build up roughly 100ml of thin slurry (per 20 liters batch) with my starter and I'll be fine?!