Remove shrimp heads, and peel shrimp, reserving heads and peels. Reserve meat for another use.
In a large stockpot, combine shrimp shells and heads along with all remaining ingredients. Add water just until all contents are covered. Bring to a simmer over high heat. Turn heat to low, and simmer for 2 to 3 hours.
Strain liquid into a clean pot with a colander or China cap. Let stand until cool, and save liquid for immediate use or freeze up to 3 months.
Recipe by Louisiana Cookin' at https://louisianacookin.com/shrimp-stock/