Seed and Bean Sprouts

Over the years, sprouted seeds and beans such as alfalfa sprouts, radish, mung, lentil, and broccoli sprouts have become a favorite addition to stir fires and salads.  The “seeds” of popularity were planted in the 1960’s and 70’s when home sprouting contraptions were all the rage. 

Outbreaks attributed to sprouts

Since 1990, raw or slightly cooked sprouts have caused an estimated 2,308 illnesses in the United States through 38 known outbreaks.  In 2011, an outbreak in Europe sickened over 2,000 people, killing at least 22.  As a result of these outbreaks, sprouts are on a list of the 10 most (unwanted!) risky foods regulated by the US Food and Drug Administration (FDA). 

Why are sprouts so risky?

The problem is that microorganisms, such as the bacteria that cause foodborne illness, already on the seeds or introduced during the sprouting process can grow quickly during germination and sprouting. The conditions are ideal—the temperature is warm, the environment is humid, and full of the vitamins and minerals that help sprouts to grow up big and strong.  And, the seeds and young sprouts can be sitting at room temperature for several days.   Even when grown commercially, sprout growing conditions can support the growth of Salmonella or E. coli.  If the pathogens ARE present, they can easily multiply to numbers that can make us sick on only a few days of sprouting. The bacteria can be on the surface of the seed/plant, or even be drawn into the plant itself from contaminated irrigation water.

To make this even a stickier problem, when producing sprouts, there historically was no step in the process that would kill or reduce the numbers of bacteria before they were eaten—most often raw or very lightly cooked in a stir fry.

It is true that the sprout industry and government regulators heeded the wake-up call when folks began reporting illness after eating sprouts in the mid-late 1990’s.  What resulted was the development of guidance and best practices for treating seed and growing sprouts.  These include better seed management strategies; seed treatment, testing and certification programs; and improved plant sanitation in seed sprouting facilities, including management of irrigation water.  But, while most of the industry has adopted these guidelines, they are only guidelines.  Therefore, the FDA still advises people at greater risk for foodborne illness to avoid eating raw sprouts. 

Advice to those who want to eat sprouts

The FDA warns consumers that to reduce your risk of illness from sprouts…just say no.  Do not eat them.  On FoodSafety.gov, the government gateway to food safety information, the advice reads:

  • Children, the elderly, pregnant women, and persons with weakened immune systems should avoid eating raw sprouts of any kind (including alfalfa, clover, radish, and mung bean sprouts).
  • Cook sprouts thoroughly to reduce the risk of illness. Cooking kills the harmful bacteria.
  • Request that raw sprouts not be added to your food. If you purchase a sandwich or salad at a restaurant or delicatessen, check to make sure that raw sprouts have not been added.

What if you are a healthy person with none of these health concerns?

The FDA and other health agencies have NOT prohibited the sale of sprouts.  If you have a healthy immune system, the risk of getting sick from these foods is much reduced.   If you choose to eat raw sprouts, do so knowing the risks and be sure to follow these tips:

  • Be sure to buy only sprouts kept at refrigerator temperature.
  • Select crisp-looking sprouts with the buds attached: avoid musty-smelling, dark, or slimy-looking sprouts. 
  • Once home, refrigerate immediately at 40° F or below. 
  • When preparing sprouts to eat, be sure to rinse sprouts thoroughly with water before use. Rinsing can help remove surface dirt. Do not use soap or other detergents.

I would like to grow my own…is that safer?

If you want to grow sprouts at home, you need to know that a home-grower runs the same risk as a commercial grower of sprouts.  It’s all about the safety of the seed—and how clean and sanitary handling practices are applied during the growing process. Remember that sprouts grow best in the same environment as the pathogens that cause foodborne illness—warm, moist, and nutrient filled. 

The most important step is to first, buy seeds that are certified (pathogen free).  You will have to ask this question as the seeds do not have to be labeled as such.  You may think that if seeds are labeled as “organic” that this might mean they are safer than conventionally grown seeds.  Do not be misled.  When a microorganism decides to contaminate a seed, it does not discriminate between conventional and organically produced seeds.  They are equally as likely to be infected. 

Also, once grown, keep in mind that sprouts are quite perishable.  If you see any signs of mold or slime in your sprout growing jar, discard everything and be sure to wash the jar with hot water and detergent and then sanitize the jar before starting again.  As soon as sprouts are grown to your liking, store them in the refrigerator at or below 40ºF.

Want to read more?

Growing sprouts, University of California, Davis

Sprouts: What You Should Know, FoodSafety.gov