Konjac

Konjac is a tropical and subtropical plant grown primarily for its large, starchy corm (underground bulb). Native to parts of East and Southeast Asia, it has been cultivated in China, Japan, and Korea for centuries, both as a food source and in traditional medicine.

The corm itself is rarely eaten directly. Instead, it is processed into konjac flour or glucomannan, a water-soluble dietary fibre that forms a firm, gelatinous texture when mixed with water and an alkaline agent. This gel is the basis for shirataki noodles, konjac jelly snacks, and various meat and seafood substitutes.

Konjac-based products have gained popularity in Western markets as a low-energy alternative to conventional noodles and as a thickening or gelling agent in processed foods.

Farmed Source
photograph to come — from twenty years of markets, farms and kitchens

How it's produced

Konjac is farmed in warm, humid climates with well-drained, fertile soil. The plant grows from a corm that is planted in spring and harvested after two to three growing seasons, once the corm has reached a usable size. Harvesting is destructive — the entire corm is dug up.

After harvest, corms are washed, sliced, dried, and milled into a fine flour. This flour is the raw material for virtually all konjac food products. Most global production occurs in China, Japan, and parts of Southeast Asia. The crop requires shade or partial shade and is sometimes intercropped with taller plants.

What it costs the planet (per kilo)

Carbon ≈0.5kg
Freshwater ≈130L
Land ≈0.4

≈ Estimated from its category — typical for vegetables, not measured for this item yet. Sources & methods →

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