Homemade ginger-garlic paste often turns an unappealing greenish-blue due to moisture and improper storage. To prevent this, it's essential to avoid adding water while grinding, as excess moisture accelerates spoilage. Instead, use dry ginger and garlic, and consider adding half a teaspoon of salt, which acts as a natural preservative. Incorporating 2-3 teaspoons of oil during grinding creates a protective barrier that reduces air exposure and helps maintain the paste's color. For extended freshness, adding a teaspoon of white vinegar can keep the paste usable for up to 2-3 months. Proper storage is also crucial; using glass jars instead of plastic can help maintain the paste's quality. Additionally, a thin layer of oil on top before sealing the jar can further prevent air exposure. For convenience, freezing the paste in ice cube trays allows for easy portion control when needed.