Check with USDA standards to grow and sell fresh blackberries. Requirements for blackberries include firmness, well-colored and developed but not overripe. Blackberries must be almost completely free of mold, decay, damage, dirt, moisture, shriveling, disease and insects. Grade Number 1 is the hardest standard to meet with the above specifications. Grade Number 2, like Number 1, cannot have more than 10 percent of the berries fail to meet requirements, but allows for no more than 2 percent to exhibit signs of decay.
Meet the USDA standards with the blackberries by carefully going through your crop and culling any fruit that doesn't meet the standards.
Sell the blackberries quickly after harvesting to avoid decay or mold growth. Choose a fruit market or store to sell the blackberries at, or sell them personally to consumers at a farmer's market or sidewalk stand.