The substance is more static than butter.
It is very difficult to preserve the pure butter since it is easily oxidized and create deodourness. Especially in warm atmosphere butter is boiled in a large pot to prepare butter oil. As a result, most of the water is removed from butter and enzyme like lipase are destroyed. The percent composition of moisture in butter oil is 1%. This butter oil is Cry static in composition and does not become spoiled at room temperature if it is kept in long tune.
Since the amount of water is very less and that is why different microorganism does not attack the butter oil easily and due to this reason, the composition of butter oil remain unchanged for a long time.