WASTE NOT, WANT NOT
Americans waste a lot of food. The Natural Resources Defense Council estimates that American households discard a whopping $218 billion worth each year — an average of $1,800 per household. Many could easily reduce that amount by actually eating, rather than throwing out, what they buy, while also cutting back on buying and cooking too much at once. In part, that means eating food before it spoils and avoiding foods that turn bad quickly for occasions such as summer potlucks.
The foods listed here are highly perishable and require proper handling when consumed outdoors in warm weather. To avoid food poisoning, the Centers for Disease Control recommends that perishable items be discarded if they remain at room temperature for two hours or more. Think twice about bringing these foods to a picnic or cookout — and if you do, transport and store them in a cooler with plenty of ice or frozen gel packs, and be sure to keep the cooler closed to keep the contents cold and safely edible.
SALADS MADE WITH MAYONNAISE
Mayonnaise, made of oil and egg yolks with a little added vinegar or other acid, is known for souring quickly. While most commercially produced mayonnaise contains preservatives that hinder the growth of spoilage-inducing bacteria, the additives don't halt bacteria growth completely. Any side dish made with mayonnaise, including potato salad, egg salad, and coleslaw, should be stored cold until eaten. At a picnic or outdoor barbecue, keep it out of direct sunlight, preferably in a cooler, or stored on top of a tray of ice. Discard after two hours if not kept chilled.
In the days before refrigeration, making hard-rind cheese was pretty much the only way to transform milk into something that could be stored without spoiling. A sliced-cheese platter is a good outdoor dining possibility, but other dairy products, including dips made with butter or soft cheeses such as cottage and cream cheese, can go bad in as little as two hours if not refrigerated. Remember, too, that butter begins to melt at 90 degrees.
Any fresh, preservative-free produce can go bad quickly, especially in warm weather. Spoilage is caused by microbes that can quickly contaminate other nearby fruit. Store a piece of fresh produce next to a spoiled one and it will spoil quickly, hence the proverb: "One bad apple spoils the whole bunch." When serving fruit, keep it cool and in the shade, and remember that cut or sliced fruit goes bad more quickly than whole fruits still protected by unbroken skins or rinds.
In many parts of the country, a fish fry is a popular outdoor get-together, especially among fishermen frying fresh catches. But it's best to avoid serving seafood outdoors as a meal, because fish and their underwater brethren go bad exceptionally quickly in an open-air environment, especially during warm summer weather.
Deviled eggs can keep up to a week in the refrigerator, but at room temperature (especially hot weather), they can go bad in an afternoon. Eggs themselves are highly perishable, and the oil or mayonnaise in most deviled-egg recipes makes matters worse. You can't always smell when a hard-boiled egg first goes bad, either. If you bring deviled eggs outdoors, transport them in a cooler, keep them on ice, and discard them after two hours if left out.
GREEN SALADS AND VEGGIE PLATTERS
When the weather's warm enough that you feel like wilting in the sun, it's a safe bet that lettuce leaves and other tasty-when-crisp salad ingredients will wilt even faster. If you do serve salad at an outdoor shindig, one safe option is to display it in an inflatable salad bar well stocked with ice. Even then, remember that vegetables kept on ice in warm weather still go bad far faster than they would in a refrigerator's crisper drawer.
SALAD DRESSINGS AND VEGETABLE DIPS
Even if salad offerings and vegetable platters stay fresh and safe, take care to ensure the dips and dressings (especially those with a dairy, oil, or mayonnaise base) don't spoil. Oil-and-vinegar dressings are apt to last longer on a hot afternoon (the vinegar's high acidity hinders bacteria growth), but oil alone can become rancid quickly if not kept cool, especially when exposed to open air.
At first thought, a "finger food" such as fried chicken might seem the perfect picnic cuisine (provided there are plenty of napkins for cleaning greasy fingers). But think again. Even properly cooked chicken can host a multitude of microbes after only a short time in warm weather. If you must bring chicken to a picnic, serve it while it's still hot from cooking or chill it completely in the refrigerator and carry it in a cooler filled with ice.
After a couple hours in warm weather, chocolate won't necessarily "go bad" in the sense of harboring dangerous bacteria, but it will melt and make a sticky, gooey mess. When chocolate is needed for s'mores or other classic summer treats, keep it in watertight plastic bags in a cooler well stocked with ice.
BEEF AND PORK
Grilled burgers and ribs are American backyard barbecue staples, so asking guests not to bring them probably isn't feasible. But be sure to handle these favorites with extra care to prevent food poisoning. Store raw meat in the refrigerator until just before putting it on the barbecue, and never let raw burger patties or pork sit at room temperature before grilling. Once these items are cooked, they should be served and eaten immediately — grilled or barbecued meats stored at room temperature will go bad almost as quickly as raw meat. Remember: Cooking meat properly kills any existing microbes, but it doesn't prevent new microbial contamination.