Pre-packing sprout salads for a 3-day rotation is generally not recommended due to the high risk of bacterial growth, even with proper refrigeration. Fresh preparation is always the safest option.
Sprouts, by their very nature, require a warm and moist environment to germinate. This same environment is also ideal for the rapid growth of bacteria like Salmonella, E. coli, and Listeria. Even if sprouts are thoroughly washed before packing, some bacteria may still be present. Over a 3-day period, even under refrigeration, these bacteria can multiply to dangerous levels, increasing the risk of foodborne illness. The pre-packing process itself can introduce additional contaminants. While some commercial sprout producers use specific sanitization methods and packaging to extend shelf life, these are not typically replicable in a home or small-scale setting. Therefore, it's best to prepare sprout salads fresh each day to minimize the risk.
If you must prepare sprouts in advance, thoroughly wash and dry them, then store them separately from other salad ingredients in a sealed container in the refrigerator for no more than 24 hours. Assemble the salad just before serving.