If you've ever seen a suitcase burst open on an airport luggage carousel and thought, "Glad that isn't mine," then you can relate to the predicament of Bob, a former student in one of the backcountry cooking classes I teach with Yosemite Association in Yosemite National Park. Bob stowed all of his edible goodies for a 5-day backpacking adventure in the thin plastic bags found in a supermarket produce aisle and tied off each bag with a twist tie. Like a bulging suitcase tied with rope, Bob's food packaging was a disaster waiting to happen.

Bob's only saving grace was that he'd bothered to put his bags of food into a nylon duffel before stuffing them into his pack, because when it came time to prepare the first night's meal he zipped open an unholy mess. Inside was a mélange of powdered milk, pancake mix, sugar, crushed crackers and a generous slathering of peanut butter. Fortunately for Bob we had plenty of extra food and spare room in our bear canisters to safely store the mess he'd created.

The moral of the story, and the one I drive home to my students all the time: the meals you plan are only as good as their packaging. The inside of a pack is a hostile environment for food-it's hot, cramped, and full of hard-edged objects-so pack each ingredient and each meal to withstand the punishment. Following are the equipment and packing tips needed to get your vittles from grocery store exit to trailhead.

Equipment:

Zipper lock bags: The genius who invented zipper-lock plastic bags has won my eternal gratitude. Have an assortment of sizes on hand before you begin packing, from sandwich to 1-gallon size, and get the heavier-duty freezer weight style with the write-on strip at the top. (Generic brand bags might save you a few pennies but if the plastic's thin and the zippers are flimsy, they aren't worth it.) Because these bags are so strong, you can give them double-, even triple-duty by bringing them home, rinsing and reusing.

Vacuum sealer: An alternative to zipper-lock bags is using a vacuum sealer like the Fresh Lock II, which I purchased at a local Sears store for $39.95. It's effective at sealing homemade energy bars, small amounts of vinegar, even whole meals. Vacuum sealing beats zipper-locks when it comes to keeping food fresh, a decided advantage if you're packing well in advance of a trip, or you're preparing food drops for long hikes.

Lexan bottles: It's a tad more expensive than Nalgene, but Lexan retains no food odor. A good bet for olive oil, vinegar and other strong-flavored liquids. Make sure you get bottles with measurements on the side.
Old prescription vials: Perfect for packing special mustards and other oozy substances needed in small quantities. Wash 'em out before using, unless you want a trace of Viagra with your meal.
Food tubes: When the weather's warm, these refillable containers do the job holding mess-makers like peanut butter and cream cheese, but when it's cold the tubes split or the clip pops off. A wide-mouth, screw-top plastic bottle, such as an old peanut butter jar, is a better bet.

Cracker protector: Crackers are a treat on the trail, but will end up as a pile of crumbs unless you stow them in a sturdy canister like an empty Pringles potato chip can. Carr's and Ritz crackers fit nicely in these cans and emerge intact. One can feeds two people for a weekend trip.

Cheese chunker: For groups of four or more out on long trips, wrap blocks of Swiss, jack or cheddar in cheese cloth (wrap each block twice around) and dip in melted paraffin wax. For smaller groups, grab gouda or edam in individually waxed rounds, or plastic-wrapped string cheese. These must have been invented with the backpacker in mind.
Pillow packs: Why bother trying to pack cream cheese, salsa, ketchup, mustard and other condiments when they're available in trail-ready, single serving containers at fast food joints?

Duffel bag: A simple, lightweight nylon duffel bag shelters your meals from cuts and punctures inside your pack, and keeps food separate from your other belongings. A duffel loads and unloads more easily than a stuff sack, and can be tied off at the handles and slung in a tree at night in locales where bears aren't too wily. But in a growing number of national parks and wilderness areas, bear canisters are suggested if not required. If canisters are available for rent, then by all means get one.

Packing It Up:

1. Start stripping: The foods we get at supermarkets are encased in plastic and cardboard that will add bulk and weight to your pack, so strip away excess packaging and get down to the barest essentials. Or buy as much of your trip food as possible in bulk at health food stores or other outlets.

2. Twist and tie: To separate ingredients going into the same pot but at different times, first pour into a zipper-lock the ingredient that's cooked last, then twist and tie off the corner. Then add the ingredient that goes in the cookpot first.

3. Write directions: Note cooking directions on the bag's write-on strip or on a slip of paper tucked into every meal bag. Label everything, even if you think you'll remember it.

4. Make meal bags: Pack every meal into its own zipper-lock bag. Preplanning, measuring, and packing complete meals consumes the better part of an evening at home, but it frees you from kitchen chores on the trail. Single bag each meal if you're using high-quality freezer bags and they're going into a nylon duffel before being packed in your backpack. Double bag meals to stave off leaks or rips if you're stuffing them directly into your pack.

5. Fill the food duffel: Spare yourself a lot of aggravation on long trips with a group by bringing at least three duffels of different colors. Load the breakfast food in one duffel, lunch/snacks in another and dinners in the third.

6. Loading into your pack: Because food is one of the heaviest and densest items you're likely to carry, it should be packed at shoulder blade level or higher in your backpack and close to your back if you'll be walking strictly on maintained trail, slightly lower if going off-trail (see Technique, October).

Cheeses and other perishable items should be tucked deep down in the pack (1/2 to 1/3 of the way from the top) to stay cool.

Snack items go in outer pockets for easy access during the day, but don't forget to include them with the rest of the food when hanging your bear bag or filling a bear canister. If you're packing a bear canister, position it about two-thirds of the way from the bottom of your pack and closest to your back for better balance. This position also puts the food in a relatively cool spot.