Scenario: Post apocolyptic USA. There's no power and no internal combustion engines. A group of people are traveling. One of the group is kidnapped and held for ransom--the group's food.
I want the group to break the prisoner out by getting the captors drunk or poisoned. But they are in an isolated area, and all they have to work with is the food and medical supplies they've brought. They have no drinking alcohol.
Could alcohol or poison be made from typical food/medical items quickly enough to make this work? They'd have a week or so, tops.