Your green tea is likely turning black due to oxidation.
Here's a breakdown of why this happens:
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Oxidation is Key: Green tea is minimally oxidized compared to other types of tea like black tea or oolong tea. The green color comes from chlorophyll, a pigment present in all plants.
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Chlorophyll Degradation: When green tea leaves are exposed to oxygen (oxidation), chlorophyll breaks down. This breakdown causes the leaves to darken and change color. The longer the oxidation process continues, the darker the tea becomes. As the reference states, "the longer the leaf is oxidized, the darker the leaf."
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Incorrect Storage: Improper storage accelerates oxidation.
- Exposure to air: Leaving the tea bag or loose leaves exposed to air is a major cause.
- Exposure to heat: Storing tea in a warm place, like near the stove, can speed up oxidation.
- Exposure to light: Direct sunlight can also degrade chlorophyll.
- Exposure to moisture: Humidity and moisture can initiate and accelerate oxidation.
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What to Do: To prevent your green tea from turning black:
- Store it properly: Keep green tea in an airtight container.
- Keep it cool: Store the container in a cool, dark place, away from heat sources.
- Use it quickly: Green tea is best when used within a few months of opening.
Essentially, the "blackness" indicates the tea has begun to oxidize beyond the level appropriate for green tea, causing the chlorophyll to break down and the leaves to darken.
