to prevent water from entering the interior of the inner container 12 and also so as to prevent grease from splashing out of the inner container 12 it can be seen that the combination of the inner container 12 and the outer container 40 provides a double wall container when they are placed in combination as shown in fig3 the end flaps 64 pivot into partial covering relation over the upper end 58 of the outer container chamber 56 so as to provide a double wall construction which minimizes the chances that the grease 38 will spill when it is desired to empty the inner container 10 the truck is driven adjacent the double wall container 10 and the lift chains 36 are attached by hooks to the lift pins 26 the lid 30 is removed then the inner container 12 is lifted upwardly out of the outer container 40 as shown in fig2 the truck can then submerge the inner container 12 in hot water if the contents are frozen so as to loosen the contents then the truck places the pivot pins 28 on pivot pin support and lowers the chains 36 so as to cause the inner.