In gas chromatography (GC), a sample is introduced into a flow of carrier gas and the mixture is driven through a heated GC column to acquire chromatographic data from the sample. During this time, the column is heated from an initial temperature to a final temperature. Subsequently, the column is cooled according to a cooling program. The cooling program may include a first cooling ramp, a subsequent isothermal hold, and a subsequent second cooling ramp. Alternatively, while the column is cooled down the flow of carrier gas through the column may be slowed down or ceased for a period of time, after which the flow of carrier gas through the column may be resumed at the original flow rate in preparation for processing another sample. Controlling column temperature and/or flow in this manner may be effective for reducing column bleed carryover and/or the effects thereof.