How many years does konjac take to harvest and how is the corm processed?

Konjac is a multi-season crop. The corm is usually grown for two to several years, lifted and replanted across seasons, to build up to a marketable size, because a first-year corm is too small for good glucomannan recovery. After harvest the corm is cleaned, sliced and dried (often into chips and then milled into konjac flour), and the glucomannan is concentrated through further processing that food-grade buyers usually handle. For a farmer the practical points are: you need patience over multiple years, good drying to avoid spoilage of a high-moisture corm, and a buyer who specifies how they want it (fresh corm, dried chips, or flour). Confirm the exact corm cycle and any processing or drying support with your KVK or the relevant research institute before scaling.