Snag-shine

Originally known as snapdragon moonshine, this alcohol is distilled from the sap of the Snapdragon Tree. While humans distill a lot of different alcohols from the various sources available to them, this is distinct in that it is brewed from a plant that grows outside the Dome. Normally such things are highly toxic to human life, or else extremely risky to consume. Even carefully prepared meat is something of an exotic delicacy in that it can potentially cause death.
But snag-shine is not toxic. It is believed that the high alcohol percentage content is what makes it more palatable. When properly made, it's deceptively sweet and easy to drink. In its lesser quality forms, it's more like drinking sugar sludge with something bitter mixed in.