The naturally occurring fatty acids and lipids in sea buckthorn are part of what makes the berry unique. In this puree-based drink, these components can separate and rise to the top, creating a distinct layer and possibly leaving a light oily film on the spoon or glass. This is completely natural for an unprocessed, puree-based product.
To use it, shake the bottle very well until the contents are fully blended. Store the closed bottle in a cool, dark cupboard away from direct sunlight or heat to help maintain the quality of these sensitive compounds. Once opened, keep it refrigerated and consume it within a few days for the best taste and freshness. The presence of these lipids contributes to the rich mouthfeel and is one reason sea buckthorn has been traditionally valued in Northern European food culture.