Observe the color: Good dried gongcai (a type of dried vegetable) has a natural and uniform color, a bright green or slightly yellowish-green. If the color is too bright or unrealistically emerald green, be wary of dyeing or sulfur fumigation. True "real green" does not fade when wet.
Smell the aroma: Upon opening the packaging, you should be able to smell a faint, natural, plant-like fragrance, without any pungent sour or chemical odor.
Feel the dryness: When squeezed, it should be very dry and firm. If it feels soft or not dry enough, it will not only be difficult to preserve, but its taste and flavor will also be compromised. Some consumers have reported that if it feels soft, it may develop a faint off-odor after prolonged storage.
Observe the rehydration: Genuine dried gongcai will quickly expand and become plump and bright green after soaking in cold or warm water, with a crisp and tender texture. The rehydration ratio is generally above 1:3.