You know how to adjust the amount of time a poison takes to produce its effects.
Prerequisite(s): Craft (alchemy) 9 ranks
Benefit(s): When you craft a poison with the Craft (alchemy) skill (whether using the normal Craft rules or the rules for spontaneous alchemy), you can increase or decrease the unit of time used to measure the frequency of a poison you craft by up to one step along the following scale: rounds, minutes, hours, days. For example, if you applied this feat to arsenic (which has a frequency of 1/minute for 4 minutes), you could increase the frequency to 1/round for 4 rounds or decrease the frequency to 1/hour for 4 hours.
Pathfinder Player Companion: Alchemy Manual © 2014, Paizo Inc.; Authors: Jason Nelson, Patrick Renie, and David N. Ross.