Sodas
Sweetened drinks can turn into a sticky mess. And if they’re left out on warm days they may go flat, or worse, burst out of their containers. Plus insects love the stuff. A better alternative is to bring partially frozen bottles of water.
Anything chocolate
Who needs to deal with a gooey mess? Leave any chocolately food in warm temperatures, and you’re likely to have more liquid than solid. A better picnic dessert is angel food cake topped with fresh fruit.
Bottles of condiments
It may seem handy to toss you condiment bottles from the refrigerator to the picnic basket, but they won’t stay cool and will just be more weight to lug around. Instead, either use condiment packages, which don’t need refrigeration, or put the needed amount of condiment in small jars and keep in a cooler.
Mayo-based salads
When potatoes, pasta, tuna, or chicken are dressed with mayonnaise, these salads need to be kept at 40ºF (4.4ºC) to remain safe from spoilage. That’s pretty chilly, even for an ice-packed cooler. A good alternative is a vinegar-and-oil dressing.
Ice Cream
Sure, there’s nothing better on a warm, sunny summer day than some ice cream. Instead of bringing it with you and risking a melted mess, plan to make a stop on the way home for some gelato.
Tough-to-cut foods
Skip any foods that require a knife. Picnic blankets and paper plates are horrible surfaces. Plan ahead and slice any foods, such as meats, before you leave.
Fried foods
When packing for a picnic, you want to minimize your waste. Fried foods, such as chicken, ensure that you’ll need loads of napkins.
Soft fruits
Fruits such as bananas and peaches may get jostled around and bruise easily on the trip. And in warm temperatures, they can become overripe in no time. Apples, pears, and oranges make better choices.
Cheddar cheese
Some cheeses, such as Camembert and brie are delightfully gooey and tasty in warm weather. But cheddar will become oily.
Deviled eggs
Leaving these out for a couple hours invites picnic-ruining germs. A better option would be hard-boiled eggs.
Traditional coleslaw
This mayonnaise-laden dish can spoil quickly. A better way to go: An Asian-themed coleslaw with rice vinegar and sesame oil as a base.