Preventing mushroom darkening: Expert tips for vibrant presentation

The delightful aroma and taste of mushrooms are not the only things that matter; their presentation is also crucial. The effort invested in preparing these delicacies can be ruined if the mushrooms start to darken—whether after being sliced or dried. Why does this occur, and how can you prevent it?

Due to oxidation, mushrooms lose their colour, darken, and sometimes become almost black. This natural process results from mushrooms coming into contact with oxygen. The same happens with potatoes, which we grate for potato pancakes and which, once turned into a potato mixture, take on a grey colour.

In both instances, you can prevent the product from darkening. To keep mushrooms' beautiful colour, use the same method as darkening potatoes: treat them with citric acid or lemon juice, for example, during soaking or boiling. A tried-and-true method is adding a tablespoon of vinegar to the boiling mushrooms. Adding some citric acid or lemon juice to the vinegar marinade used for pickling mushrooms is also beneficial, ensuring that the preserves do not darken.

Dried mushrooms will inevitably change colour somewhat, and nothing is alarming about it. Only a genuinely dark, almost black colour indicates that something went wrong during the drying process. If the mushrooms are black after drying, it may mean they were dried at too high a temperature. Too high a temperature would be above 60°C.

The optimal temperature for drying mushrooms is between 40°C and 50°C. However, it is worth noting that mushrooms containing a lot of water, such as slippery jacks, should be dried at even lower temperatures—around 30°C. Once a significant amount of water has evaporated, the temperature can be gradually increased to a maximum of 50°C.