According to one aspect of the invention there is provided a method of drying a body of grain, comprising storing the body of grain in an elongate bag silo 10, providing at least a first outlet 22 intermediate a first end 16 and a second end 18 of the bag and at least a first and a second inlet (26, 28), situated intermediate the outlet 22 and the first end 16 of the bag. The second inlet 28 is spaced longitudinally further away from the first outlet 22 than the first inlet 26 and the first outlet 22 is the closest outlet to the second inlet 28 in a direction towards the second end 18 of the bag 10. The method further comprises providing a flow of air, between the inlets and the outlet such that a pressure differential between any of the inlets is maintained within a predetermined threshold.