Due to persistent moisture in the jars or trays. Trays (plastic transparent trays) are difficult to sterilize. I use jars, and I hot wash them in the dish washer before every use.

There are also techniques that limit contamination in jars. First, use the proper amount of seeds, approximately 2 tbsp per quart. That will avoid overcrowding and allow some air flow.

Second, If you are careful to turn them upside down often while the roots are actively growing, you will get a ball of sprouts not attached to the screen, and better airflow. If you let roots grow into the screen, airflow will be severely limited.

Third, some sprouts are better than others at not blocking airflow. Broccoli have very fine rootlets and are the worst, and fenugreek one of the best. I am discontinuing broccoli once I am through this seed bag.

For shoots, I do not see a problem. It is just micro greens grown in a tray of compost. For both sprouts and shoots, I let them grow until they can, and that helps cleanliness.

I would also add that the bacteria that can not be eliminated are those coming from the seeds themselves. I have never done it, but if you have trouble perhaps you can consider quickly rinsing the seeds in a bleach solution (1tbsp per gallon or so), before first soaking.

Interesting. Thanks, glib. It all sounds like a lot of work, so I might just go the route of growing microgreens instead,

Frankly, I think that sprouts are a lot less work than micro-greens. But that may be because I grow them in the house. I would be more comfortable in a green house. I grow a tray of sunflower shoots also, continuously. For that, I have to bring some compost in from the garage, wait for it to thaw, fill a tray, seed it, water it, and cover it with a clear plastic lid. They will produce a lot of shells that need to be swept, harvesting is done with scissors, and finally I have to dispose of the soil outside.

While pricier, you can get seeds for sprouting that have been tested for pathogens. I do not do a lot of sprouts, but my mung bean seeds came from Peaceful Valley. Now, if I could just get them to grow longer...

Do more people get sick from sprouts than from lettuce? I'm thinking of the lettuce recalls over the past couple of years, but no sprout recalls come to mind. (But I could have missed it, I follow the news sporadically.) Anyway, the bacteria are related to the moisture like glib said. I use trays that go through my washing machine, and I like them better than jars because they have better drainage. But I was thinking of bacteria re:sprout success/failure, not worried about my health. I also always rinse my sprouts and dry them before storage/use. Basic food handling safety.

People died in Europe from eating organic sprouts because animal manure was used as fertilizer - that's where the pathogens came from. Sprouts are kept moist, so the pathogens thrive until eaten.

Then they were shoots. Joe Nitpick.

Sprouts are grown without medium, so why would anyone put manure on them? Sounds like food handling safety practices weren't followed there, and not following good fhsp can make any food unsafe, especially if done on a large scale.

Pathogens can grow in plain water...no need to add manure and stir. Ever throw out a vase of flowers that made you gag?

Well, that wouldn't be plain water then, it would have a broken plant stems leaking out lots of nutrients. And if you're trying to make a correlation to sprouts, you are not supposed to have them sitting in water either. It's part of what I like about my trays, good drainage.