Flaxseeds come in two different colors, a golden yellow or a deep, dark brown. Both types of seeds can be eaten whole or ground up, and are valuable for their nutritional content. Flaxseeds are rich in omega-3 fatty acids, and this, along with their nutty taste, make them a regular addition for salads, baked goods and even soups. You can keep flaxseeds in your pantry, freezer or fridge, but storage requirements depend greatly on whether the seeds are whole or ground up.
Flax and Its Shelf Life
Flaxseeds, because of their high oil content, can go bad very quickly. Whole seeds have a longer shelf life than ground seeds. Whole flaxseeds, because of their hard, shiny hulls keep for upwards of one year at room temperature. Ground flaxseed goes bad quite quickly. It should not be stored at room temperature unless in a vacuum-sealed container. Kept at a cool temperature, ground flaxseed stays fresh for up to 90 days.
Storing Flax Correctly
While it's okay to keep whole flaxseeds in an open container, it's best to keep them in a sealed food-grade container to keep out dust, debris and insects. You can leave whole flaxseeds on your kitchen counter or in a pantry, but storing them in your fridge prolongs shelf life, so do so if you plan keep them for more than a year. Ground flaxseed needs to be stored in the refrigerator or freezer. Keep it in an airtight container and, to protect it from light exposure, use an opaque rather than translucent container.
Purchasing and Keeping Fresh
Flaxseeds can be purchased whole or ground up in grocery stores, health food stores and bulk food suppliers. Only buy whole flaxseeds in bulk -- meaning in non-prepackaged quantities -- as flaxmeal does not last long. Bulk purchases make the most sense if you are planning on using flaxseeds regularly or in significant amounts, such as for your weekly baking of multigrain bread or your daily smoothie. When buying whole flaxseeds, look for unbroken, shiny seeds. Do not buy ground flaxseed that is past or close to its best-buy-date, as ground flax goes rancid easily. Buy only ground flax that is stored in an opaque, air-tight package. Once opened, use your ground flax within 5 weeks. Because flax is easy to grind at home with a coffee grinder, blender or food processor, the best option for fresh ground flax is to buy whole seeds and grind at home as needed.
How to Tell If Flax Is Still Good
Fresh flax has a crunch and a nutty, slightly toasty flavor that becomes pronounced when it is are cooked, as in the case of baked goods. If your flax has a skunky or overly bitter flavor, your flax has gone rancid and should not be eaten. Similarly, if your flax — ground or whole — has a dusty taste, it likely was not stored properly and has gone bad and should not be eaten.