If they get good and hot, like if you leave them in direct sun for a long time, they'll get icky. Not make you sick icky, but ketchup separates and turns brown and acidy, and mayonnaise can separate and get kind of mealy. Mustard also loses its texture, but is the least gross. The syrup depends on what's in it. I don't know why it says dry, because one would think the packets would be water tight.

Is the shell on your truck a contractor's shell and just shaped metal? Or is there some kind of insulation and lining? When it sits in a parking lot in the sun for a few hours, do the things inside feel hot? If yes, then you should insulate your packets so they don't overheat. You can use an old cooler that leaks for an insulated pantry box, or an insulated lunch or grocery bag, or even just wrap some towels or blankets around the box they're in.

Consider, though, that if it's too hot in the truck for the ketchup, it's too hot for the bread, too. It'll go all steamy, then get moldy, stale or both, unless it's chock full of preservatives. The fruit will also start to turn, and the cookies will go limp. This is why old coolers make such good pantries. A cheap styrofoam cooler isn't as good, but will work, especially if it doesn't get blazing in the truck.

Before loading up a cooler, put a block of ice in for half an hour (freeze water in a disposable container, or freeze a can of non-carbonated drink--a bag of ice will probably cool it faster, but it's wetter which isn't as good for things like bread). Then remove the ice (possibly to your non-leaky, cool storage cooler), dry up anywhere condensation might have formed and load in your food. The point is to have the air inside cool before you fill it. If you're going to be driving all day and plan to picnic, it helps to put aside what you'll be using that day. If you don't, try to open the cooler in a cool, shady place, even if that's just inside the back of the truck, take out what you need, and keep the cooler closed until you need to put things away.

That sounds laborious, but it's really not. Try to imagine how you'll be using your foods and pack accordingly. It's gotten us through camping in Moab, Utah in high Summer amongst other inhospitable places. :)

BTW, old, leaky coolers are also great for transporting hot foods.

Edit: I forgot to say: If you take items out of a pantry cooler for a picnic and they get hot, don't put them back in the cooler! It'll just keep the heat in them and help them to get that much weirder. Put them in a paper bag at most in that case.

This post was edited by plllog on Sat, May 17, 14 at 0:13

Great advise plllog.

Another thing to consider. These items (especially the liquid ones) don't have a long shelf-life to begin with due to the type of packaging - some sources say 6-months to 1-year.

The hotter the storage temperature (each 10-degrees F above 70-degrees F), the shorter the shelf-life. The cooler the storage temperature (each 10-degrees F below 70-degrees) the longer the shelf-life. "Optimum" storage temperatures for the longest shelf-life would be between 40-60-degrees F; and at those temperature it can double the shelf-life of food. This is true for ALL food you store, not just condiment packets. Heat can affect the acidic ingredients, artificial sweeteners, and some food textures.

As an example, you would think something as benign as military MRE's (Meals-Ready-to-Eat - the epitome of food designed for long-term storage) would last nearly forever, but that's not true. My Army Officer son-in-law gave me a storage-life projection sheet for MRE's from his first deployment to the "Sandbox" in the middle-east. When MRE's are stored at 70-degrees F (which is considered room temperature), estimated storage life is 100-months. Stored at 100-degrees F - 22-months. Stored at 120-degrees F, which the interior of your camper shell can easily exceed during hot weather, the storage life of an MRE is 1-month.

And as to why it says "dry".... Dry storage is also optimum for all food storage - humidity around 50% or lower. High humidity (as well as high heat) can affect the seals on the packages.

The 5 "deadly enemies" to stored food are:
1. Heat
2. Light
3. Moisture
4. Oxygen
5. Insect infestation

-Grainlady

Wow, thank you! You all have come through for me again, and I appreciate it! We have an old insulated cooler that is still good and doesn't leak, but because it has no wheels or a pull-handle, we no longer use it. It's the traditional, older style, metal outside, insulated and plastic inside, made by Coleman years and years ago. (I think we've had it at least 32 years.) Maybe that's what it will be used for now.

Our truck's "camper shell" seems to be fairly insulated. It has windows that we've only opened a few times. It doesn't get obnoxiously hot, but it does get warm!

Donna

Donna

Interesting, Grainlady! I didn't know the seals on the packets would fail. Which is a good reason not to put them in an ice chest with ice, which will become a lake. :)

Donna, the old Coleman cooler will work great. Because it's older, and not as well insulated as the double walled plastic coolers, and because the metal shell is something of a conductor, and because there are windows in your shell, it will help if you put something over the cooler. A picnic blanket, big jacket, spread newspapers, beach towels. It doesn't matter what you use. Just put a few layers of fabric over it to give it some more insulation, especially against sun beating in the windows. This isn't vital given that it only gets warm back there, but it's a good habit to get into.

BTW, a good way to tell how well insulated a cooler is is putting your hand flat when it's been loaded up with ice and food for a few hours. If it feels cold, it's not so well insulated. If it feels room temperature, it's very good. Average for newer, small coolers, is feeling slightly cool.

On a serious note: Never think a cooler is proof against bears. They have powerful noses, and they also know where food is stored. They will rip open cars to get it. Be careful when you bring food into bear country.

We are aware that about bears and cars. Good reminder, though, as we will be going into a couple of areas where bears have been known to do just that (one is Yellowstone). We'll leave the green cooler in the motel room and take only what we need for that day's picnic.

Donna

Donna, I can also tell you that catsup will ferment. When we owned the bar/grille, bottles of catsup left unrefrigerated in the kitchen (where it was hot) would bubble and actually ferment, you could smell it. So, even if sealed, I'd be careful about heating the catsup. I think the mayo would separate, but the mustard would be OK, I've carried those packets in my glove compartment with no ill effects on mustard. The syrup, I'm assuming, is not maple syrup, but some Mrs. Butterworth's/etc. type? There's so much sugar in that that I can't believe anything would happen to it other than, as mentioned, the seals could fail.

Have fun and travel carefully.

Annie

The syrups are those little ones from Smuckers. They aren't full of sugar, though -- or at least, they're not supposed to be, as they are labeled "sugar free". I don't have too many of those, though. Then I have about 32 envelopes/packets of Kraft Free Italian dressings that will go with us.

My husband has opened the boxes of all of these, and transferred what he thinks we'll need, into Ziploc bags. Then he put them in the old Coleman cooler. On another website, I saw how someone fashioned a cover for her cooler -- she made it from a silver insulated sun-shade that you'd use on your windshield! That was so cool! I don't know if I will have time to do something like that before we leave, but I understand the science and importance of keeping the box cooler.

I was telling my husband, the Ziploc idea was a great one. I'd like to take a couple of boxes of cereal on the trip, but they always get beat up. Putting the cereal inside a Ziploc bag, labeling it, and recycling the box would be a much better idea!

Donna