Flaxseed oil is sensitive to air, light and warmth, so storage matters more for this oil than for many refined cooking oils. The product description specifically says to store it carefully after opening to prevent oxidation.
Best practices:
- Keep the cap tight whenever the oil is not being used.
- Store the bottle in a cool, dark place, preferably the refrigerator, rather than on a counter or near the stove.
- Take it out just long enough to pour, then put it back.
- In the fridge the oil may become cloudy or thicken — this is normal and does not affect how it can be used. Let it sit at room temperature briefly if you want it to pour more easily.
The product information does not specify an exact after-opening period, so use the label as the first guide. As a general rule, treat opened flaxseed oil like a perishable food: use it regularly, and do not keep an open bottle for many months. A 100 ml bottle is small enough to be finished within a reasonable time if you use it for salads, porridge, cottage cheese or smoothies.
Check freshness before each use. If the smell becomes sharp, sour or strongly fishy, the oil has oxidized and should be discarded. Do not use oil that is past its expiry date or that tastes rancid.