90%
Button mushroom yields 90%
You buy button mushroom by its whole weight, but you only plate 90% of it. That 10% loss is real cost the invoice never shows — here's the math.
Yield is the fraction of an ingredient that actually reaches the plate after you clean, peel, and trim it. What you pay is the AP (as-purchased) price; what it costs on the plate is the EP (edible-portion) price.
Trimming the dry stem ends is the only real loss — mushrooms are nearly all usable.
Say your invoice shows $3.50 per lb of button mushroom (an example AP price).
At 90% yield, your real cost is $3.89 per lb EP — because $3.50 ÷ 0.90 = $3.89.
AP price is illustrative; the EP figure is computed (AP ÷ yield). Use your real invoice price below.Sourced: CIA Standard Yield Tables, via the Plate Cost Calculator · what yield means · edible portion