'Shroom 101: The shopper's guide to mushrooms

Natural health food
Mushrooms are an ideal food: they contain negligible amounts of fat, sugar and salt but are a valuable source of dietary fibre. They have more vegetable protein than most other vegetables.

They're also a good source of the B vitamins: niacin, riboflavin, thiamin, folic acid and pantothenic acid. These vitamins are often lost as so many vegetables are cooked in boiling water. Mushrooms are also one of the few dietary sources of vitamin D.

Finally, they also contain the minerals potassium, copper, phosphorus and selenium, which boost your immune system and energy levels and help lower blood pressure.

The supermarket spotter's guide to mushrooms
The increasing popularity of vegetarianism and healthy eating has led to an explosion of mushroom varieties available in supermarkets. And with mushroom recipes increasingly specifying the best variety for the dish, consumers are demanding more and more exotic fungi.

White mushrooms
White mushrooms account for the majority of mushroom sales. They're picked at four stages (grades) of the growing cycle and can be bought as:

• Button
• Closed Cup
• Open Cup
• Large Flat

A Button mushroom, not picked, will double in size every 24 hours. In five days it will grow into a Large Flat mushroom. As a mushroom increases in size and maturity, so its flavour develops.

By far the most popular mushroom is the Closed Cup mushroom. This can be used whole, sliced or quartered on pizzas, chopped into pasta sauces, added to casseroles or tossed into stir-fries.

Open Cup mushrooms are the best variety to use for garlic mushrooms and are delicious sautied with bacon. Large Flat mushrooms are ideal for stuffing.

Brown mushrooms
These have a firmer texture and stronger, nuttier flavour than white mushrooms. They are sold in two sizes; the smaller ones are called Chestnut, Crimini or Portabellini mushrooms. The larger ones, with the gills showing underneath, are called Flat Chestnut or Portabello mushrooms. Use them in the same way as white mushrooms.

Over the page: Exotic varieties