Nutritional and environmental variables have important documented effects on the growth and development of edible mushrooms. However, published research on the specific effects of different cultural techniques is lacking. The aim of this project was to evaluate the effect of mycelium exposure during fruiting with 0.5”, 1”, 1.5”, 2”, and an unrestricted opening (5”) on yield and fruit size of Hericium erinaceus in a commercial production setting. Data revealed that all restricted openings resulted in higher yield than an unrestricted hole. A further effect on variance in bioefficiency was observed in the 1.5” treatment, which had the greatest bioefficiency at 68% after one flush, as well as the lowest variance. Results for size demonstrated an inverse correlation between average fruit size and hole size i.e., smaller holes resulted in larger fruit. Both bioefficiency and size findings will be of use to gourmet and medicinal mushroom growers. Increasing bioefficiency, reducing harvest variance, and achieving consistent average fruit sizes can all impact operations and sales of H. erinaceus crops.