If your kitchen is too cold, you can create a warm spot using the heat from the lightbulb in your oven. Place the jar of starter on a baking sheet inside your oven. Shut the door and turn the oven light on. (Do NOT turn the oven on.) The heat from the lightbulb will create a warm environment inside the oven. Check on it after an hour or two to make sure it isn't too hot inside.