Smell

Floury

One of the most characteristic and frequently mentioned smells in mycological literature is the floury smell (farinaceous). This aroma often surprises beginners: a mushroom that smells like a bakery, freshly ground flour or raw dough is a very unusual thing to find in a forest.

24 species in the database.

The chemistry of the floury smell

M.Ya. Zerova in her «Key to the Fungi of Ukraine» often uses this term when describing species that grow in pastures, meadows and forest edges. Chemically, this smell comes from the volatile compound trans-2-nonenal — the very same substance responsible for the smell of fresh cucumber or watermelon rind, which is why many people perceive this aroma as a mix: "flour with notes of cucumber."

David Arora in «Mushrooms Demystified» singles out the floury smell as a critical marker for several well-known edible mushrooms:

1. St George's mushroom (Calocybe gambosa): This spring edible mushroom grows in "fairy rings" in pastures and has an incredibly strong, dense smell of fresh raw dough or wet flour.

2. The miller (Clitopilus prunulus): An autumn mushroom that grows in deciduous forests. Its strong floury smell is the main feature that lets you tell it apart from the poisonous funnels (Clitocybe). This smell is exactly why it is often called "the miller."

3. Knights (Tricholoma): Many species of grey and brown knights have a distinct floury aroma when cut.

Roger Phillips stresses that to detect a floury smell (if it is faint), you must rub a piece of the gills or flesh between your fingers.

Questions and answers

Are there poisonous mushrooms with a floury smell?

Yes. For example, some poisonous pinkgills (Entoloma sinuatum — the livid pinkgill) can also have a floury smell, sometimes mixed with an unpleasant smell of rancid fat. So a floury smell on its own does not automatically make a mushroom safe.

Why is the smell described as both "floury" and "cucumber-like"?

It is a matter of individual perception of the volatile nonenal molecule. Some people smell raw wheat dough in it, others freshly cut green cucumber or pumpkin. In mycology these terms are often synonyms (farinaceous/cucumber).

How do you get rid of this smell when cooking?

For many people a floury smell in a finished dish is unpleasant (it can leave an aftertaste of raw dough). To get rid of it, boil the mushrooms (for example, St George's mushroom) for 15 minutes first and drain the water. After that the esters break down, and the mushrooms can be fried or stewed.

Sources

1.Зерова М.Я. та ін. Визначник грибів України. 1979
2.Roger Phillips. Mushrooms (Roger Phillips)
3.David Arora. Mushrooms Demystified
4.Index Fungorum