Store Mushrooms in Paper, Not Plastic
Mushrooms are mostly water and respire (release moisture) after picking, and a sealed plastic bag traps that moisture against the mushrooms, encouraging sliminess and mold within a couple of days. A paper bag — or the mushrooms' original cardboard punnet loosely covered — lets that moisture escape while still protecting them from drying out completely, extending fridge life to a week or more.
Sources & methodology: These tips draw on established food-science references —
Harold McGee's food-science writing, America's Test Kitchen /
Cook's Illustrated testing, Serious Eats'
technique reporting, USDA food safety guidance,
and peer-reviewed food-safety research (including UC Davis
cutting-board studies) — not reworded recipe-blog consensus.