You’ve got two problems: You want to keep food from spoiling on your backpacking trip, but there’s no way to lug a refrigerator around with you to keep perishables cold.

Fortunately, there are two solutions we’re going to talk about here: dehydrated and freeze dried food. (We’re assuming you don’t want to heavily salt everything like sailors did to preserve pork back in the day.)

The idea behind all of these preservation methods is to reduce the moisture content in fruits, vegetables, and meat, making snacks and meals alike last much longer than they would when properly hydrated. Low water content keeps mold, bacteria, and other organisms that thrive in moist conditions at bay. But the processes used to get the water out in dehydrated vs. freeze dried food are very different, so the finished products have unique properties.

First, how it’s done. If you like science, you’ll love this:

Dehydration dries food out by heating it and constantly removing the warm, moist air that rises from it as it gets hotter—but not so hot that it cooks. Freeze drying takes the opposite thermal approach, as the name implies, and dries food out via cold. Edible items are first frozen, then thawed in a vacuum that causes the water to sublimate, which means it turns directly from a solid to a gas, skipping the liquid middle step.

While both methods alter the food, dehydration’s effects are particularly obvious, as the heat and moisture removal cause whatever was dried to shrivel a bit. Freeze dried food retains its basic appearance and shape.

Another difference: Freeze dried food is lighter and typically remains safe to eat longer than dehydrated food, but the longevity factor only matters if you plan to store your meals for at least a decade or so before cracking them open. The weight difference, however, makes freeze died food the cuisine of choice for some backpackers, especially those who count every ounce they carry.

Studies have shown that both methods retain a perhaps surprising amount of nutritional value, though certain beneficial components—like vitamin C—tend to break down during the preservation process. These studies are also often linked to survivalist scenarios, in which people are living off of their stored food after a natural disaster or other emergency. A week on the trail with nothing but freeze dried food isn’t going to give you scurvy.

If you’re looking to make a choice based on texture or flavor, you may want to do a taste test before you plan your meals. Some people say dehydrated food requires a good dose of spices, while others insist that the process concentrates natural flavors. Freeze dried foods, on the other hand, taste like they should, though a piece of fruit gains the texture of Styrofoam®. You can use water to reconstitute ingredients or a whole meal on the trail. Dehydrated food can be revived when soaked in hot water, while freeze dried food just needs to get wet. Keep in mind that heat typically increases enjoyment of meals, because who likes cold lasagna? 

Perhaps the biggest practical difference between the two food preservation methods comes down to control. Dehydrating food at home is a relatively simple and inexpensive process, which means you can pick out exactly what you want to eat and prepare it yourself. Freeze drying is more complicated and expensive, so unless you’ve invested several thousand dollars into an industrial-type machine, you’re going to have to buy the dehydrated food that’s already available on the shelf.

As with anything you bring on the trail, the choice comes down to personal preference. Freeze dried food and its dehydrated counterpart will both certainly do what they’re supposed to do: keep you alive and give you energy to always move forward—and they can even taste good while doing so. Don’t forget that you don’t have to live exclusively off of one type of food or the other. You can even mix and match. Remember that both methods have been used to preserve fruit that makes its way into a particular staple of backpacking: trail mix.