Cultivated Mushrooms.
Half a kilogram of mushrooms in a hot pan releases about a cup of water. Until that is gone, nothing browns.
A mushroom is the fruiting body of a fungus: a spongy mass of fine threads with walls of chitin rather than cellulose, about 92 % water, and very little fat. Its threads hold water loosely, so in a hot pan mushrooms first shrink and release a pool of liquid, then — once it has boiled away — brown deeply (VIII.1). How long the first stage lasts depends on how much water there is and how fast the burner can boil it off (II.6): a crowded pan on a weak burner stews mushrooms for many minutes; batches in a wide, hot pan, or a powerful wok burner, get them to the browning stage quickly. Salt draws water out sooner; add it once they start to brown if you want them firm.
Mushrooms are rich in glutamate and, once heated, in guanylate, which multiply each other's savouriness (XI.5): they give meat-like depth to vegetarian dishes and stocks. Drying concentrates it: dried shiitake (香菇), soaked in cold water for hours and then cooked, are among the most umami-rich ingredients there are, which is why they anchor Chinese and Japanese vegetarian stocks (XXII.2, XXII.3). The workshop boils off the water.
Below: the energy and minutes needed to heat mushrooms of the weight you choose from 20 °C to 100 °C and boil off the 40 % of their weight they release before browning (exact energy balance with water's specific and latent heats), on burners delivering the power you choose to the pan.
- Explain why mushrooms release water before browning.
- Use pan size, batches and heat to brown them.
- Use mushrooms and dried shiitake for umami.
- Know the danger of wild mushrooms.
Boil off the water, then brown; dry for depth
Mushrooms are about 92 % water. Driving off the 200 g that 500 g release takes about 619 kJ: about 9 minutes on a home burner delivering 1.2 kW, 5.2 on a strong burner, 2.6 on a wok burner — and a kilogram on a home burner needs about 17 minutes, which is why a big batch in one pan stews. Cook mushrooms in batches in a wide pan, with a little oil, over high heat; leave them alone until they release their water and it boils away; then add butter, garlic and salt as they brown.
Washing is fine: mushrooms take up surprisingly little water when rinsed briefly, far less than they release in the pan; just dry them. Soak dried shiitake in cold water for several hours or overnight, then use both the mushrooms and the strained soaking liquid. Store fresh mushrooms in a paper bag in the fridge. And never eat mushrooms gathered wild unless an expert has identified each one: the death cap (Amanita phalloides) looks ordinary, tastes fine, and its toxins, which cooking does not destroy, cause liver failure days later.
Cook 500 g of sliced mushrooms in one crowded pan and the same amount in two batches in a hot wide pan. Time each until the liquid is gone and they start to brown.
Terms
- Fruiting body
- The part of a fungus that makes spores: the mushroom.
- Chitin
- The tough polysaccharide of fungal cell walls.
- Guanylate
- A nucleotide that multiplies the savouriness of glutamate (XI.5).
- Death cap
- Amanita phalloides, a deadly wild mushroom.
Sources
- USDA FoodData Central, SR Legacy (April 2018), public domain.
- IAPWS, Revised Release on the IAPWS Industrial Formulation 1997 for the Thermodynamic Properties of Water and Steam (IAPWS-IF97), region 4 (saturation).
- S. Yamaguchi, "The synergistic taste effect of monosodium glutamate and disodium 5'-inosinate", J. Food Sci. 32, 1967: y = u + 1218·u·v, concentrations in g/dL.
- H. McGee, On Food and Cooking: The Science and Lore of the Kitchen, 2nd ed., Scribner, 2004.