How long does everyone typically let a starter go for before pitching? I've usually waited a day and try to pitch than the krausen is up but was thinking about pitching one around hour 14 tonight.

Fourteen hours of incubation time is more than long enough for a 1L starter that was inoculated with a vial of White Labs yeast that is less than 4 months old. Most strains take less than 6 hours to exit the lag phase (many will exit the lag phase in less than 3 hours). The average White Labs vial contains 50 billion viable yeast cells when pitched (100 billion at time of packaging). Yeast cells divide approximately every 90 minutes after the lag phase has been exited, which means that the culture will contain approximately 100 billion cells 90 minutes after exiting the lag phase. A 1L starter that was pitched with 50 billion viable cells will reach maximum cell density approximately 3 hours after exiting the lag phase, or roughly 9 hours total for most yeast strains. Given enough O

_{2}, carbon, physical room to grow, the time to reach 400 billion cells is approximately 10.5 hours, and the time to reach 800 billion cells is approximately 12 hours.

A key point to remember is that the yeast biomass grows exponentially, not linearly. The growth rate is 2

^{n}, where n equals the number of minutes that have elapsed since exiting the lag phase divided by 90. The equation for calculating the approximate number of cells at any point during incubation given an initial cell count is:

cell_count_at_time_n = initial_cell_count * 2

^{(elapsed_time_since_exiting_the_lag_period_in_minutes / 90)}The equation shown above is bounded by O

_{2}, carbon, and media volume.

One last thing, starters should be incubated at room temperature.