Outdoor cooking differs substantially from kitchen-based cooking, the most obvious difference being lack of an easily defined kitchen area. As a result, campers and backpackers have developed a significant body of techniques and specialized equipment for preparing food in outdoors environments. Such techniques have traditionally been associated with nomadic cultures such as the Berbers of North Africa and the Plains Indians and pioneers of North America, and have been carried down to and refined in modern times for use during recreational outdoors pursuits.
Currently, much of the work of maintaining and developing outdoor cooking traditions in Westernized countries is done by the Scouting movement and by wilderness educators such as the National Outdoor Leadership School and Outward Bound, as well as by writers and cooks closely associated with the outdoors community.
The type of food common in outdoors settings is somewhat different from what is normally available in a kitchen, and also differs depending on the type of activity the cook is engaging in. While someone at a public campground may have easy access to a grocery store and be able to prepare plenty of recipes with fresh meat and vegetables, someone on an extended trip into the backcountry will not be able to carry large amounts of fresh food due to water content, and will have to rely heavily on dried meats, vegetables, and starches such as ramen, polenta, and dried potato flakes. Wilderness experts in both categories sometimes make use of locally available wild foods as well, particularly wild vegetables and fruit but also occasionally fresh fish and wild game; however, it is not unusual for camping food, especially backcountry food, to be partially or totally vegetarian.
Camping food is often very high in fat and carbohydrates to provide energy for long hikes, and hikers (much like soldiers) must rely heavily on energy-packed snacks such as trail mix, chocolate, energy bars, and even synthetics such as sports drinks. Water can also be at a premium, so important parts of a camper's pantry include chlorine or iodine-based water disinfectants as well as drink mixes to mask the flavor of the chemical treatment.
Recipes are often designed with significant planning and home preparation in mind, with certain ingredients mixed at home and then cooked on the trail; to that end, there are a number of providers of freeze-dried food, both ingredients and full meals, to the outdoors market, and just-add-water instant meals (including hot cereals, pasta or rice in sauce, and instant soup) from the supermarket are popular as well. Alternately, some wilderness experts advocate bulk rationing, in which each hiker is given a selection of raw ingredients and prepares a meal from scratch on the trail.
Camp frying pans are generally made out of very thin metal (though some campers do use cast iron pans for this purpose as well), so extra care must be taken to evenly cook the food, especially over the small-diameter flame of a portable stove. A "round the clock" technique, where the frying pan is moved repeatedly to expose different parts of its base to the flame, is the most commonly recommended solution to the problem, though it is also possible to use a flame diffuser to achieve the same effect. For campfire use, on the other hand, some camp cooks prefer a legged cast-iron pan called a "spider", which is elevated to allow a small fire directly beneath it.
An improvised griddle can be made by putting a flat stone directly on the fire (or above it, on top of other stones). Food is then placed on the stone.
In backpacking particularly, boiling water is the most common kitchen operation undertaken on the trail, used for cooking or reconstituting food, making hot beverages, cleaning up, and even sanitizing drinking water. Portable stoves are therefore generally rated in terms of how quickly they can boil a liter (or other appropriate size) of water; indeed, some commercial stove models are specifically optimized for fast boiling, with other operations such as frying or baking being an afterthought.
Like camp frying pans, camp pots are generally made of very lightweight material (often aluminum or, at a considerable price premium, titanium). Though less of a worry given the thermal mass of water, the camp cook must still take care not to allow food to burn, since the pot itself has very little mass to spread the heat out.
A pot hanging over the fire, although picturesque, may spill, and the rigging may be difficult to construct from found wood. Generally this is done with metal rigging, much of it identical to that historically used in home fireplaces before the invention of stoves. Two vertical iron bars with an iron cross-piece allow pots to be hung at various heights or over different temperatures of fire. Griddles, grills and skewers can also be hung over the fire. When working with wood, one may use two tripods, lashed with tripod lashings, but the rope will be liable to melt or burn. Dovetail joints are more secure, but difficult to carve.
A good alternative to cooking with a tripod is to cook directly upon the fire itself. To do this properly the fire needs to have a reasonable bed of coals and to have burned down to the point where it is not a roaring fire. While the pot may be set directly upon the coals, this is not preferable since that will tend to extinguish the coals. To lift the pot up off the fire, often two small logs of similar size may be used on either side of the pot; camp-style Dutch ovens have three legs built into the pot to perform this function. This allows continued airflow through the fire while providing optimal heat. The one down side to this form of cooking is that the pots will become blackened with soot and ash, which can be difficult to scrub off. The ash and soot build up can be easily avoided by applying a thin layer of dish soap (preferably biodegradable) to the outside of the pot before cooking. The ash and soot will stick to the soap which is then easily rinsed off later.
With plants such as bamboo, steaming too is possible. In this method, a piece of bamboo is set diagonally above a fire. The bamboo is perforated from within (between the joints) and water is placed in the lowest bamboo segment. Food (e.g. rice) is then placed in the top segment which is steamed due to the water evaporating (because of the fire) in the lowest segment.
The original form of covered cooking is the earth oven, simply a covered pit with a fire built in it, demonstrated in techniques such as the Polynesian umu, the central Asian tandoori, and the Native American clambake.
Another commonly used technique is the baking of food in aluminum foil packets. Food is wrapped inside a durable packet of tin or aluminum foil, crimped to seal, and placed on or under hot coals. Baked potatoes are commonly cooked this way but entire meals can be cooked in one packet. Besides aluminum or tin, organic material (tree leaves) are also frequently employed. Tree leaves such as those from the banana tree do not burn/ignite as they contain enough oil to resist the heat from the flames (at least until the frying is complete). The way to adapt recipes where food is wrapped in foil is to use a barrier such as baking or silicone paper between the food and the foil; the overall technique is similar to the en papillote technique developed in French cuisine, but uses a more robust container.
Other simple methods include clay wrapping food (such as in the kleftiko method used in Greek cuisine), leaf wrapping, and plank grilling, where food is cooked on a wooden plank set vertically next to the fire. Hot-stone cooking, where food is placed on a heated stone next to or even in the fire or where fire-heated stones are dropped into a pot are other methods.
Long-distance truckers, automotive travelers and rally racers have occasionally resorted to cooking on accessible sections of the vehicle engine; the book Manifold Destiny, though written to a certain extent as a humor book, is considered the authoritative reference on the subject. The food is usually wrapped in several layers of aluminum foil and secured onto the engine block or other hot parts of the engine.
In some areas where there is a significant amount of steady, less-hazardous volcanic activity, lava cooking (invented in Hawaii) is sometimes practiced as a novelty. The food does not come in direct contact with the molten rock, instead being wrapped in a moist barrier (usually wet tropical leaves such as banana foliage or ti leaves). The wrapper is sacrificial, and is chipped or otherwise cleaned off along with the cooled lava before serving.
Portable stoves are widely used in areas where fuel such as wood is scarce or there is a significant fire or environmental hazard to building a campfire. Such devices usually use a liquid fuel (usually a petroleum derivative or some kind of alcohol), but gaseous fuels like propane and solid fuels such as wood shavings and hexamine are also used depending on the stove design; while two-burner models are commonly used for front-country campstoves and function much like residential gas stoves, backpacking stoves generally put out a much more concentrated and less powerful flame and require lightweight cooking equipment made of aluminum or titanium rather than more typical kitchen-type utensils.
In addition, there are often special techniques for baked goods made on the trail in the absence of specialized camp oven equipment, including flipping over the (lidded) pan while on the heat and the "twiggy fire", which mimics the use of charcoal on the lid of a Dutch oven using a small campfire on the lid of the pan.
Solar cookers are sometimes used in places where absolutely minimal environmental impact is required.