I purchased the Mr. Malty calculator on my iPhone, but I'm a bit confused on what the growth rate is. All I see is a number going from 2.00 up to 6.00. What does that mean? I see where the packs and liters change, but it just doesn't make a lot of sense to me.
That number is the amount you want to grow the initial yeast. If you set it to a growth rate of 6 the original yeast will be allowed to multiply 6 times.
. Put a ridiculously large brew in (like 20 gallons of a 1.100 wort) and move the slider and you will see the number of yeast vials change.