Unrefined amaranth oil is sensitive to light, heat, and oxygen, all of which can accelerate oxidation and alter its taste. After opening, store the bottle in a cool, dark place—ideally a pantry or cupboard away from direct sunlight and heat sources. If you live in a warm climate or want extra protection, keep the oil in the refrigerator; the cool temperature slows oxidation and extends shelf life. Use a tightly sealed container to limit air exposure; if the original bottle is large, transfer a portion into a smaller dark‑glass jar for daily use. Avoid leaving the cap off for long periods, and use the oil within a few months for best flavor. When you’re ready to use it, let the bottle sit at room temperature for a few minutes so the oil reaches its optimal consistency.