Select your substitute based on dish type: lemon zest for raw, lemon juice or tamarind powder for cooking, and citric acid or DIY blend for dry spice applications.
Prepare the substitute by zesting, juicing, or mixing powders as needed to maintain correct ratios.
Apply the substitute using the recommended ratio: generally 1 teaspoon substitute per 1 teaspoon sumac, except citric acid at 1:4 ratio.
Adjust seasoning and consistency by tasting and adding more if necessary; keep in mind moisture additions for liquid substitutes.