How to blanch chives to remove oxalic acid

It is recommended to blanch chives in boiling water for 30 seconds to 1 minute to remove oxalic acid. The removal rate of oxalic acid can reach over 50%. The key steps include sufficient water supply, high fire throughout the process, and timely cooling.

1. Water Control

The blanching container should ensure that the water volume is at least 5 times the volume of the chives, to ensure that the water temperature does not drop sharply after being put into the pot. Oxalic acid is easily soluble in water, and sufficient water can accelerate its dissolution. It is recommended to use a soup pot with a diameter of over 20 centimeters and keep the water level at 70% full for home use. Boil the water before adding the chives to avoid nutrient loss caused by prolonged soaking.

2. Control the temperature

Keep the oxalic acid crystal structure in a boiling state at high temperature throughout the process. insufficient firepower can lead to prolonged blanching time, significant loss of chlorophyll, and yellowing of chives. It is recommended to adjust the maximum firepower of commercial stoves, and for household gas stoves, water can be boiled to boiling before serving. If the color of the chives turns bright green, they can be removed.

3. Time Management

Blanch wide leaf varieties with thicker stems for 45 seconds, and control fine leaf varieties within 30 seconds. Use a spoon to constantly flip and evenly heat, ensuring complete immersion at the junction of stem and leaf. Exceeding 1 minute will damage active substances such as chive extract. You can use chopsticks to lightly poke the stem to test its softness and hardness.

4. Cooling treatment

Immediately add ice water or flowing cold water after removing it, and rapid cooling can stop the waste heat from continuing to destroy nutrients. The soaking time in cold water should not exceed 2 minutes to avoid the loss of water-soluble vitamins. When draining, gently press with your hands to remove surface moisture, and do not twist or twist forcefully to prevent cell rupture.

5. Secondary treatment

For individuals sensitive to oxalic acid, secondary treatment can be performed by blanching for 10 seconds before changing to new water and blanching for another 20 seconds. When paired with high calcium ingredients such as tofu, calcium can combine with residual oxalic acid to form calcium oxalate that is not easily absorbed. It is recommended to mix cold dishes with a small amount of cooking oil to form a protective film and reduce nutrient loss.

Blanched chives are suitable for quick stir frying or cold mixing over high heat, avoiding prolonged stewing. The recommended daily intake is within 100 grams, and patients with kidney stones should limit themselves to 50 grams. Eating with colored peppers or kiwi fruits that are high in vitamin C can help promote iron absorption. When storing, wrap it in kitchen paper and put it in a fresh-keeping box. refrigeration should not exceed 24 hours. Special populations such as gout patients can consult a nutritionist to develop personalized plans before consumption.