USDA Updates Federal Mushroom Grade Standards

The U.S. Department of Agriculture is revising its grade standards for fresh mushrooms, updating the guidelines to better reflect how mushrooms are produced, handled and marketed today.

USDA’s Agricultural Marketing Service announced the changes Aug. 25 following a request from the mushroom industry. The revised standards will take effect Sept. 24.

Among the most notable changes is the creation of a federal grade specifically for portabella mushrooms. USDA is also separating mushroom size from grade requirements, updating tolerances for product defects and revising terminology, definitions and defect-scoring guidelines.

The agency said the revisions are intended to align federal standards with current marketing trends and provide greater uniformity when mushrooms are bought and sold.

Federal grade standards provide a common language that growers, packers, wholesalers, retailers and other buyers can use when describing product quality. Although their use is voluntary in many transactions, consistent standards can simplify buying specifications and help reduce disagreements over product condition.

Under the existing system, mushroom grades include criteria involving maturity, shape, trimming, open veils, disease, spots, insect damage and decay. Size classifications have traditionally been included within individual grade requirements.

Separating size from grade will allow buyers and sellers to specify mushroom dimensions independently from overall quality, potentially offering greater flexibility for different retail, food-service and processing applications.

Adding a portabella grade also reflects changes in the mushroom category. Portabellas have developed into a significant retail and food-service item, but the federal standards historically were built primarily around traditional white mushrooms.

USDA is also revising allowable defect tolerances to better reflect current production and handling practices.

The changes arrive as the mushroom industry continues working to increase category visibility and consumer demand. Just days before announcing the revised grading standards, USDA approved an increase in the assessment supporting the Mushroom Promotion, Research and Consumer Information Program.

That assessment will rise in two phases during 2027, providing additional funding for mushroom research and promotion.

For retailers and suppliers, the updated grade standards are less visible than a new variety or packaging change, but they influence the specifications and terminology used throughout the supply chain.

By bringing those standards closer to current market practices, USDA hopes to provide growers and buyers with a clearer and more consistent framework for marketing fresh mushrooms.