Hello BudgetAnalyst98. A fishy or seaweed-like aroma in matcha usually points to a high content of amino acids like L-theanine, which is common in shaded green teas, but a distinctly unpleasant *fishy* taste combined with being discounted strongly suggests improper storage and early-stage oxidation. When matcha is exposed to light, heat, or air, it degrades quickly.
To determine the exact cause, check the color and packaging. Dull, yellowish-brown powder means oxidation. If it was sold on discount, it was likely near or past its expiration date and stored in a warm warehouse.
Unfortunately, once matcha has oxidized and developed off-flavors, you cannot fully restore its original vibrant flavor profile. However, you can salvage the product by masking the fishy taste. Here are a few steps to use it up safely:
1. Use it exclusively for heavy-flavored baked goods like matcha cookies, pound cakes, or brownies where strong butter, sugar, and vanilla can mask the off-notes.
2. Whisk it into heavily sweetened lattes using flavored syrups or condensed milk.
3. Store whatever is left in an airtight container in the freezer to halt further degradation.
