In this activity, learners make a small batch of biodiesel that will work in any diesel engine. Learners use an old juice bottle as a "reactor" vessel to chemically process vegetable oil into fuel. Learners will discover that making biodiesel is much like cooking, since both are forgiving of improvisation and both require careful technique. This step by step instruction guide includes safety recommendations because the home-brewing process involves flammable, poisonous, and caustic chemicals, alcohols, and lye. Follow all directions carefully and ensure a responsible adult is present.