Kelp contains alginic acid and alginate, substances that are insoluble in water yet possess strong water-absorbing and swelling properties. Once hydrated, a viscous gel forms on the kelp's surface, preventing further water penetration, making it difficult to fully soak. Additionally, most of the iodine in kelp is concentrated on the surface, and prolonged soaking causes iodine loss.
The common practice is to soak dried kelp in water before cooking, but this is actually incorrect. Kelp prepared this way will remain tough no matter how long or how thoroughly it's stewed. So how can kelp be cooked until tender? Here are a few simple, easy-to-follow tips to make your kelp cook tenderly—take note!
1.Rice-washing water method: Use rice-washing water when soaking kelp. It helps the kelp expand and clean easily, and makes it tender when cooked.
2. The right amount rule: During cooking, pick up a piece with chopsticks and pinch it. If it's soft, immediately remove the rest of the kelp. Overcooking will make it tough.
3.Alkali Trick: Adding a small amount (not too much) of baking soda or baking powder while boiling makes kelp tender, delicious, and more flavorful.
4. Vinegar Trick: Adding white vinegar when boiling kelp shreds not only removes their fishy odor but also helps soften them faster and enhances their color. For extra tenderness, extend cooking time slightly.
5. Spinach Pairing: Adding a few spinach leaves prevents kelp from disintegrating.Adding spinach may cause the kelp to disintegrate. 5. Dry Steaming Tip: Separate clumped dried kelp and steam it in a bamboo steamer over water for about 30 minutes. Then soak it in clean water overnight. Kelp prepared this way becomes crisp yet tender, perfect for stewing, stir-frying, or cold salads.
6. Blanching Method: For kelp knots used in soups, briefly blanch them in boiling water before cooking to remove any fishy odor. This yields a more flavorful broth.
How to Select Kelp?
When choosing dried kelp, opt for pieces with a "white frost" coating.When purchasing dried kelp, consumers often notice a white powdery layer on its surface. Many mistakenly believe this is salt crystallized during drying, while others even suspect it indicates mold or spoilage.
In reality, this "white frost" is a substance called mannitol.Not only is this substance harmless, but it also offers medicinal benefits such as lowering blood pressure, promoting diuresis, and reducing swelling. Additionally, it possesses anti-cancer, antibacterial, hangover-relieving, and weight-loss properties. Therefore, when selecting dried kelp, opt for pieces with this "white frost." Also, choose kelp that is drier, dark brown or brownish-green in color, with relatively uniform leaf pieces and consistent thickness.
When purchasing, it's best to unfold the kelp to inspect it. If small, broken pieces are mixed in, it indicates poor quality. Holes or large areas of damage may suggest insect infestation or mold growth during storage.
Friendly reminder: Kelp is rich in iodine and contains valuable mannitol on its surface. Therefore, avoid prolonged soaking, beating, or vigorous stirring, as these actions can cause significant nutrient loss. When cleaning kelp, also ensure the soaking water isn't excessive—generally, use no more than 2500 milliliters of water for every 500 grams of kelp.