Cassareep is a dark, concentrated seasoning produced from processed cassava juice, sometimes with spices. It gives Guyanese pepperpot its characteristic color and bittersweet depth. It is distinct from caramel coloring, molasses and ordinary cassava flour.
Use a properly produced food product. Raw cassava and its juice can contain cyanogenic compounds, and this definition is not a method for making them safe. Cassareep also should not be treated as a guarantee that a cooked dish can be stored unrefrigerated.
Reference: Further reading.