This Is the Best Way to Cook Mushrooms, According to Science

There are a multitude of ways to serve mushrooms. Smothered in butter and sat atop toast, stuffed with garlic and cheese, stirred into creamy risottos for that rich, umami flavour …

We all have our favourite shroom recipe, but scientists from the Mushroom Technological Center of La Rioja (CTICH), Spain—yes, an actual thing—claim to have worked out the optimal way of cooking the edible fungus.

The researchers set out to find which cooking method—grilling, frying, microwaving, or boiling—best preserved the nutritional profile of the vegetable. Mushrooms are rich in fibre, vitamins, and protein, and low in calories and fat, but can lose these properties during cooking.

So, according to the study, if you want to get the most from your mushrooms, you should step away from the frying pan and the boiling water. The cooking methods that give the best nutritional results are grilling and microwaving.

The study, which was published in the International Journal of Food Sciences and Nutrition, analysed the nutritional profile—before and after cooking—of four of the most commonly eaten mushrooms: white button mushrooms, shiitake mushrooms, oyster mushrooms, and king oyster mushrooms. Scientists found that frying (unsurprisingly) increased mushrooms' fat content and caused significant loss of protein. Boiling also caused a notable loss of vitamins.

However, when researchers grilled and microwaved mushrooms, not only were there no significant nutritional losses, but the antioxidant levels within the vegetable increased. The authors concluded: "Since cooking techniques clearly influence the nutritional attributes of mushrooms, the proper selection of treatments is a key factor to prevent/reduce nutritional losses."

Commenting on the findings in a press release, Irene Roncero, researcher at CTICH and one of the study's authors, suggested that preparing mushrooms in oil or water caused soluble nutrient compounds to escape when cooking. She said: "Frying and boiling treatments produced more severe losses in proteins and antioxidants compounds, probably due to the leaching of soluble substances in the water or in the oil, which may significantly influence the nutritional value of the final product."

Roncero continued: "When mushrooms were cooked by microwave or grill, […] there are no significant losses in nutritional value of the cooked mushrooms."

However you decide to cook your fungi, keep in mind the wise words of culinary doyenne Julia Child: never crowd the mushrooms.