Global Composting and Screwtech have invested in the development of the hoppers used in current HotRot systems. Waste that is heterogeneous is generally wet and sticky and is often corrosive or abrasive. Many wastes are prone to compaction that can cause bridging and retard aeration. Hoppers need to be able to handle wastes where properties may change daily, weekly or seasonally and where waste change from site to site.

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The HotRot hoppers are designed to eliminate compaction zones that not only cause wear but dramatically increase drive sizes and power consumption. Hoppers are designed to be fully enclosed, containing any free-draining liquids but also preventing access by vermin; enclosing the hopper also enables odours to be controlled and safety features incorporated that disable drives if hopper lids are open. Feed hoppers are usually manufactured using stainless steel although marine-grade epoxy coatings are sometimes used.

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Hoppers, like the HotRot units, are designed for outdoor installation but it is often desirable to enclose the hopper/s in a building to help control odours during periods when waste is being loaded.