How to master the dehydration step in shiitake mushroom processing

Dehydrated shiitake mushrooms with good commercial value have bright yellow gills, a plump shape, uniform size and a rich aroma. To process good shiitake mushrooms, mastering the "dehydration step" is crucial.

1. Timely harvesting: this is the basis for ensuring the finished mushrooms have bright color. The main reason shiitake mushrooms become discolored during drying is that the mushroom bodies are injured before drying. To overcome this shortcoming and enhance the mushroom bodies' resistance to external pressure, timely harvesting is very important. They should be harvested when the partial veil has fully split and the cap has curled upward like a gong. Do not spray water in the 4 hours before harvest; harvest using the "twist-harvest method", and handle gently during harvesting, cleaning, stem removal and transport, putting them into the drying chamber for dehydration within 3 hours after harvest as far as possible.

2. Control the temperature: this is the key to the plump shape of the finished mushrooms. To keep the mushroom bodies plump after drying and shaping, suitable temperature conditions should be created, so that the outward diffusion and inward diffusion of free water molecules inside the shiitake tissue are as synchronized as possible. This requires frequent observation and frequent turning during drying, reasonably mastering the heat, and controlling temperature and humidity well. That is, under the condition of 35-40°C, dry steadily for 4 hours, then stop the fire and cool; when the caps become soft, gradually increase the fire to raise the temperature to 55°C; when the mushroom bodies are 90% dry, stop the fire again and open the chamber to sort them; when the temperature drops to ambient temperature, raise the fire again to 60°C and maintain for 1-2 hours. The finished mushrooms dried in this way shrink uniformly inside and out, with almost no wrinkles on the surface, and are of good quality.

3. Strict grading: this is the guarantee of uniform size in the finished mushrooms. When the mushroom bodies are dried to 90% dry, take them out quickly and line them up for sorting, manually selecting and grading by size, removing mushrooms with sand and mud, deformed mushrooms and mushrooms with damaged gills, while trimming excess stems, then sifting through screens according to export standards, and then raising the fire again until fully dry (moisture content 11%-13%). After cooling to ambient temperature, seal and store them in double-layer plastic bags of 6-8 si for sale.