Where does the core contamination risk for raw alfalfa sprouts frequently originate?

On the seed surface before or during the sprouting process

The fundamental safety hazard associated with raw alfalfa sprouts does not generally stem from the mature alfalfa plant or issues occurring late in the growth cycle, but rather from contamination that is already present on the seed stock before the sprouting process even begins. Seeds can acquire pathogens either in the field during cultivation or during the harvest and handling stages. When these contaminated seeds are placed into the necessary warm and humid environment required for germination, two things happen critically: the seed dramatically increases its water content, and its surface area expands significantly. This creates an ideal setting where any pre-existing bacteria can rapidly multiply, leading to widespread pathogen levels that cannot be eliminated later without cooking.