How to Avoid Foodborne Bacteria at a Picnic

You can't see, smell, or taste the foodborne bacteria that cause illness. Food that smells or tastes spoiled, on the other hand, gets that way thanks to a type of bacteria that usually won't make you sick.

Whether you're hosting or attending an outdoor eating fete, bacteria is the last thing you want to worry about at a picnic. Here, a few basics on what to choose.

Debating between a hot dog and a burger? Hot dogs are less likely to contain harmful bacteria, since they're fully cooked before they're packaged.

Just be sure to eat it cold. Since melons grow on the ground, they can have E. coli or salmonella on the surface. Scrub under running water, dry well, and keep cold to prevent bacteria from multiplying to a risky level.

Dips that are tomato-based or contain vinegar or citrus are usually fine because these acidic ingredients keep bacterial growth to a minimum.

Salads that have a lot of vinegar or store-bought mayonnaise in them are safer thansalads that do not, again because of the acidity, which actually kills pathogens like E. coli and salmonella if the salad is dressed for at least 15 minutes.

A block of cheddar may get sweaty in the heat, but any cheese that's not made with raw milk tends to be resistant to bacterial growth. Crackers—as well as chips and cookies—are also safe bets, thanks to low moisture levels and high-heat baking, which kills pathogens.

Fruit pies tend to be perfectly safe at room temp (the sugar in them slows bacterial growth), but you might want to steer clear of custard- or cream-filled desserts if they've been out for more than a couple of hours.