Margaret Eby for Food & Wine cites the excellence of two southern Chester County businesses that are pillars of our nation’s mushroom industry: Laurel Valley Farms and Phillips Mushroom Farms.

Laurel Valley of Landenberg is owned by five of the region’s major mushroom farms in a co-op arrangement. Its excellence starts from the ground up: It is the largest mushroom composting facility in North America.

Each mushroom farm has its own substrate formula and its own regulations.

Once the compost is mixed, pasteurized, and optimized for both temperature and pH level, the business’s experts inoculate it with a proprietary fungal culture that each farm provides. The proprietors then distribute it to growing facilities to continue the life cycle.

“The quality of mushrooms depends on three things,” said Jim Angelucci, the general manager of Phillips Mushroom Farms in Kennett Square. “The genus, the quality of the substrate, and the art of the grower.”

Phillips is one of the many local mushroom farming operations that jointly produce about two-thirds of all mushrooms sold in the U.S.

Read more about Laurel Valley Farms and Phillips Mushroom Farms in Food & Wine.