In Phu Tho, alongside renowned specialties like ca thinh (fermented fish), thit chua (sour meat), and banh san (cassava cakes), there’s a humble but equally appealing dish made from a local leaf: pickled cassava leaves (also called sour cassava leaf pickle).

Nguyen Giang from Thanh Son, Phu Tho said the main ingredient for this specialty is cassava leaves. However, locals only use leaves from native cassava varieties for pickling, avoiding high-yield cassava varieties due to potential toxicity.

“Sticky cassava leaves are the best for pickling. Locals also prefer red cassava leaves over white ones, as white cassava can cause dizziness,” she explained.

Leaves from cassava plants growing along fences or field edges are preferred over those from cassava grown for tubers. These wild cassava plants have smaller, tender, and soft shoots, resulting in tastier dishes.

Moreover, these cassava plants are easy to grow and can be harvested nearly year-round, except from December to February when cold weather hinders sprouting and new growth. During this time, leaves tend to be tough, bitter, and less suitable for pickling.

According to Giang, to make delicious pickled cassava leaves, select tender shoots with 2-3 medium leaves (neither too young nor too old), plump, and still covered with a fine powdery coating at the tip.

Freshly harvested cassava leaves should be processed immediately to retain crispness and freshness, ensuring the best flavor after pickling.

First, remove old or wilted stems and leaves, wash thoroughly, soak to reduce sap, and then crush the leaves by hand.

The crushing process requires skill to soften the leaves without tearing them, preserving their original shape. Afterward, rinse the crushed leaves several times with water to clean them thoroughly, then pack them into jars, pots, or crocks.

Add cooled boiled water or filtered water to cover the leaves, press them down with a heavy object, and seal the container tightly.

“This type of leaf doesn’t need salt to ferment well. Some people may add salt for a bolder flavor and longer preservation, or use warm water or rice-washing water to speed up the souring process,” Giang noted.

For cleaner and tastier pickled cassava leaves, it’s best to use ceramic or porcelain containers.

After packing into jars or crocks, the leaves can be sun-dried for a few hours and then moved to a shaded area to speed up fermentation. Typically, pickled cassava leaves are ready to eat after 3-5 days and don’t become overly sour or mushy like pickled mustard greens if left longer.

Thao Trinh