I am hoping somebody can give me info on the cons or lack thereof (I hope) of pitching appropriate quantity of properly stored yeast that have exhausted their energy reserves (glycogen and trehalose) besides longer lag times and thus increased chance of infection (which I am not worried about).
When I can I harvest yeast from the primary to use for the next batch but due to time lapses I usually feed the yeast between batches; accordingly fermentation takes off in less than six hours. For the first time I pitched harvested yeast after six days in the fridge and the lag time was approx 18 hours. Since everything else was equal (pitching rate, oxygenation, wort temp) I assume the increased lag time is due a lack of consumed energy reserves / state of dormancy.
So, other than the yeast taking longer to 'wake up' and get kicking, and thus the increased chance of undesired microbes propagating, does a longer lag time hurt anything? The only thing I can imagine might be an issue is increased esters, but not sure why.