Biological efficiency (BE) is the mushroom grower's yield metric: the fresh weight of mushrooms harvested divided by the dry weight of the substrate they grew on, expressed as a percentage. A block of 5 lbs dry substrate that produces 5 lbs of fresh mushrooms has 100% BE — a frequently cited benchmark in the mushroom-growing community, though typical and achievable ranges vary widely by species and substrate (see the related reading for specifics).
BE matters because substrate is the grower's main consumable cost, so it is the cleanest read on whether a batch was worth the inputs. Tracking BE per strain, substrate recipe, and flush tells you which combinations actually pay and which are quietly losing money even when the fruiting looks healthy.
In inventory-and-costing terms, BE is simply a domain-specific yield figure: it is the bridge between substrate consumed (an input) and finished mushrooms produced (the output of a production run), and it feeds the per-pound cost the same way yield does for any other maker.
Related terms
Yield
The amount of usable finished product a recipe or production run actually produces, after accounting for trim, waste, and loss.
Production Run
A recorded instance of producing goods using a recipe. Deducts ingredients from inventory, adds finished goods to stock, and tracks batch/lot numbers for traceability.
COGS (Cost of Goods Sold)
The total cost of materials, labor, and overhead directly tied to producing the goods you sell. Tracked automatically through purchases, recipes, and production runs.
Recipe
A defined set of ingredients, quantities, steps, and equipment needed to produce a finished good. Recipes automatically calculate production costs based on current ingredient prices.