On a recent trip I ran across a guy who had just spent the night out away from his camp, unintentionally. He left his plane and camp thinking he was taking a short day hike and didn't get back until noon the next day. He seemed like a pretty experienced person, just subject to a set of circumstances he couldn't overcome before it got too dark to travel. It wasn't raining and it wasn't that cold, but it wasn't warm, either...maybe low 40's and damp. I asked if he got a fire going and he said no...no matches and "too damp where I was anyway". That part surprised me. A skilled woodsman can always get a fire lit. But the worse you need a fire, the harder it is to obtain.He was an experienced outdoorsman and climber, but he left his camp woefully unprepared for one of the most fundamental survival chores. Luckily he just had a miserable night and not a fatal one.
Lots of people fancy themselves expert fire starters because they've successfully lit fires under ideal conditions, given a healthy enough supply of paper and matches. Lighting fires under poor conditions, which is the only condition where you really need a fire is a different story. The worse you need it, the harder it is to accomplish. I have seen people who couldn't keep a fire going with a bottle of charcoal lighter and a blow torch. That's not an exaggeration...that's what they were actually using (unsuccessfully) to try and light a fire on a summer afternoon with no wind and low humidity. Entertaining as it was to watch, it's a good reminder that NO ignition system is foolproof. The technician has to do their job well regardless of the source of ignition, and the only way to get good at it is to practice. If you don't regularly light fires in poor conditions you're unlikely to have success in even moderate conditions when you're stressed. The information here is a primer to explain how to light a fire under adverse conditions, but if you don't practice your results will likely be sub-par.
There are lots and lots of ways to start a fire...bow drills, hand drills, flint-and-steel, fire pistons, magnifying lenses, even the bottom of a soda can polished with wax or chocolate can be made into a parabolic lens capable of starting a fire under the right conditions. But for our purposes we'll concentrate on the simpler, more foolproof methods: matches and lighters. If you can regularly get a fire going under adverse conditions with nothing but the bit of glowing tinder from a bow drill, you needn't keep reading. Anyone who's traveling in (or flying over) the backcountry without a flame source and a knife on their person is just as unprepared and negligent as a pilot who doesn't check his oil level before going on a flight. There's just no excuse for it. We'll also discuss ferrocerium rods since they have some advantages over matches and lighters (and many disadvantages) and are relatively easy to use with a little practice.
Matches come in many sizes, with wooden kitchen matches being the most popular in the woods. They produce a reliable though small flame provided they are kept dry, and they're easier to maneuver into position than the flame from a lighter. Strike-anywhere matches are sadly not what they used to be, and if you have the option it's best to use the red phosphorous striking surface needed to ignite safety matches. The problem with matches is they are pretty bulky for the amount of fire they provide, they won't light if exposed to even small amounts of moisture, and they're easily extinguished by wind.
Stormproof matches solve many of the problems inherent to matches and lighters. They provide a long lasting hot flame and are immune to wind and short term moisture. They are bulky, but it's unlikely a person will need more than one match if they've built their fire correctly. Regardless of which matches you cary, replace them often with fresh matches. They do not last forever.
Lighters, which today almost universally means disposable butane lighters, have the advantage of providing a lot more fire than an equivalent mass of matches. They are still susceptible to wind, but re-flicking a lighter is faster and more convenient than digging out another match. They're a great fire source and they're very reliable, and they can be used with one hand, but there are some significant drawbacks. For one, they're mechanical devices with several moving parts manufactured overseas by the lowest bidder. For another, the gas leaver can be depressed in a pocket or pack and leak all the butane out...something you're not likely to notice unless you're a smoker and use the lighter regularly. Also, they don't work when wet, since water prevents the ferrocerium "flint" from producing a spark, and once wet they can be difficult to dry out.
Refillable lighters like the Zippo are wonderful inventions and as nostalgic as paper shotgun shells and jack knives, though not nearly as reliable. Even without use the lighter fluid evaporates in a matter of days leaving them sturdy, beautiful, and worthless. Don't count on them unless you smoke a pipe and light one up fifty times a day and refill it nightly. If all you have is a zippo that's out of fuel, pull the cotton stuffing out of it and spark it with the flint. That will often work when the wick won't light.
One of the most inexpensive ferrocerium rod fire starters available: The Gerber Bear Grylls Fire Starter. Click to purchase on Amazon.com. The even more compact Light My Fire "Swedish Firesteel 2.0 Army" model. Click to purchase on Amazon.com.These are metal rods which produce a spark when scraped with something hard like the back of a knife blade. Sometimes they come in a plastic housing with a built in scraper. They produce a spark much easier than a flint and steel, and they make you look cool. They last a long time if stored properly, and if used exclusively they will make a person a better fire starter, or at least a better collector of tinder. The problem with them is they are a poor ignition source...they are useless against fuel that will readily ignite from a match. The spark that comes off a ferro rod is hot, but small and brief. It has no ability to pre-heat or dry out even very fine tinder. For a ferro rod to work the tinder has to be ready to burst into flame with the least provocation and assistance. This means incredibly fine, perfectly dry tinder or tinder resplendent in oils. Ferro rods work best with prepared tinder like petroleum-soaked cotton, rubber cement, or commercially produced fire starters like Wetfire. They will also work with superior natural tinder like shredded birch bark, very fine shavings of resin saturated wood, the shredded inner bark of black poplar, bunches of completely dry grass or old mans beard (moss), and very fine, plentiful shavings of perfectly dry wood. Tinder like this can be extremely hard to find, especially in an emergency, making the ferro rod a very poor choice for a primary fire starter.
Ferrocerium rods come in all sizes. A small one can be kept in a match case in place of one match, but it must be wrapped in aluminum foil or coated in finger nail polish or it will react with the matches and dissolve. A very skilled woodsman can use one to ignite natural tinder, but they are a poor substitute for a match. Ferro rods work best with prepared tinder, and vaseline soaked cotton balls are among the cheapest to make and longest lasting. Commercial fire starters like WetFire work well but have a limited shelf life. Rubber cement burns ferociously and will ignite even when it’s "dried out." Small tubes are available at bicycle stores. A tube of Vaseline lip therapy does double duty in a survival kit... fire starter and skin protector.
Cotton balls impregnated with vaseline ignite easily from a ferro rod and burn well for several minutes, and they don't dry out over time if kept in a tight container. Some people stuff vaseline soaked cotton balls into short lengths of plastic drinking straws and then heat seal the ends, making a "fire straw."
As impressive as the sparks look, they only last a fraction of a second and are not nearly as effective as a match flame in igniting even good tinder. This pile of fat wood shavings would not ignite from repeated spark showers, though with better technique they would light. If you’re going to cary a ferro rod spend a good deal of time learning how to use it or leave it at home.
Very find shavings from dry wood will ignite with a ferro rod, though the larger shavings probably will not. This size of wood shavings will not ignite from a ferro rod unless they are completely dry.
In addition to their other drawbacks, ferro rods are awkward to use. The scraping motion needed to make a spark requires a firm surface to work from and has a frustrating tendency to disrupt the tinder pile. Still, used properly they will get a fire lit and they're the bees knees for sparking up a petrol-fuel camp stove. Just don't rely on one unless you're a true expert or you also cary a supply of prepared tinder with it.
Speaking of prepared tinder, in addition to carrying a source of ignition some people also cary a quantity of flammable material to assist in lighting a fire. This can be a good idea, but it's not foolproof. Among people who like to build kits, fire-making kits are a favorite. There are so many things that burn well and it's fun to put them together. Everything from rubber cement to vaseline soaked cotton balls to dryer lint to traffic flairs are touted as the end-all-be-all for lighting a fire. There are two major problem with these kits. First off, they are seldom available when you really need to get a fire lit. Folks might cary their kit with them on a day hike the first couple weeks or months after they make it, but eventually it gets left behind for something you KNOW you'll need, like an apple or chocolate bar or just the cool-back comfort of not wearing a pack. If it won't ride in the pocket of any and all your outfits, it's going to get left behind. A small match case might give you less "firepower", but it's much more likely to be with you when you need it.
The second problem with fire starting kits is they encourage people to be sloppy in their fire building, relying on a superior ignition source rather than correct preparation and execution. While a bit of rubber cement or vaseline impregnated cotton can be a great help in starting a fire, it won't make up for sloppy fuel selection or arrangement. A person who regularly lights their fires with an accelerant they cary with them is unlikely to be able to light a fire with only a match and the materials at hand when they need to.
In almost every environment there is good fuel, as well as poor fuel available for a fire. Most of the time the difference between the two is how much moisture it's absorbed. Remember, there is no such thing as "dry ground". Wood in contact with the ground will always be wetter than wood suspended off the ground. Dead branches still attached to a tree are protected from the ground moisture as well as from precipitation. Alder thickets always have dead wood in them and alder is one of the easiest woods to gather without tools. In conditions of heavy rain look for the most vertical dead trees as they absorb less moisture than trees leaning towards the horizontal. A straight standing dead tree three inches in diameter will have dry wood at it's core even after extended rain, though you'll need an axe to get to it.
Tinder collection is critical; it's what grows the fire when the very least energy is present. Without sufficient tinder the flame from the match will never grow enough to ignite the kindling. In pine forests the prime tinder available is pine pitch, either in lump form or as resin saturated wood. Pine pitch burns ferociously but like candle wax it requires a "wick" in the form of needles, twigs, or wood shavings. Pitch saturated wood needs only to be cut into pieces small enough to light from a match. In addition to how well it burns, pitch saturated wood is waterproof, thus always dry and ready to burn, even if laying on the ground.
Globs of pine pitch can be broken off with a knife or fingers. Added to the top of a pile of dry grass, twigs, pine needles or wood shavings the pitch will dramatically increase the intensity of the fire.
Resin saturated wood occurred where a conifer tree has been injured in the past and is redly identifiable by the shiny, pitchy look and the strong turpentine smell of the cut wood. Shavings can be made from a piece too big to move, or from a standing tree.
It's called building a fire. Not "piling up" a fire, or "heaping" a fire, or "slapping together" a fire. Just as a pile of building material doesn't make a house when you throw a nail on it, a pile of wood doesn't make a fire.
While a bit oversimplified, fire is made up of correct proportions of heat, fuel, and oxygen. If you have these three things in proper proportion, the fire HAS to burn. it's impossible for it not to burn! But if either of these three things is out of proportion, the fire will burn poorly or not at all.
For our purposes, solids and liquids do not burn; only gases burn. For the woody, cellulose materials found in wild land fuels to combust they have to reach a temperature where the solid material turns to gas. It's that gas which actually combines with oxygen in the air and combusts. The courser the material is, the greater the heat needed to raise it to the outgassing, or combustion point. When sweat evaporates from your damp shirt it takes heat with it and cools you down. The same thing happens when moisture is present in the fuel. When woody material is wet or damp, the heat source has to first heat the water to the evaporation point and hold it there until the cooling of evaporation no longer prevents the outgassing of the cellulose fiber. Thus the damper the fuel, the smaller it has to be for a small heat source like a match to be able to evaporate the water and raise the material to the combustion point.
It's hard to overstate how the ambient environment affects the combustion of common fuels. On a warm day with low humidity, wild land fuels will burn as much as 50% faster in direct sun than they will in shade. In cold and damp conditions the greater humidity and cooler temperatures found directly on the ground can significantly retard combustion compared to the warmer and drier air found at chest level. The colder the ambient environment, the greater the temperature spread between the starting point of the fuel and the combustion point. Conditions of high humidity and low temperatures are the most difficult in which to start a fire, and conversely they are the exact conditions when a fire is most needed.
Lighting a fire is like setting up a line of dominos that continually grow in size until the last domino is the size and weight of a tomb stone. The slight energy required to topple the first domino starts a chain reaction that will topple that last tomb-stone-sized tile, but only if each successive domino is correctly placed and sized. The energy from your match dries out and heats the fine tinder until it combusts, creating a slightly larger flame. That flame dries out and heats the coarse tinder and fine kindling, which in turn ignites the course kindling, which has enough energy to now ignite finger and wrist-thick fuel and so on. For this to work the tinder, fine kindling, course kindling, and fuel not only have to be correctly sized and proportioned, but they have to be correctly spaced. If the fuels are too far apart the transfer of heat is inefficient and the reaction stops....the domino falls flat without hitting the next one. If the fuels are too compressed then the evaporating water cannot escape and heat cannot freely travel through the fuel to dry and heat the next link in the combustion chain...the dominos are too close together and there's not enough space to build up energy.
Here we have tinder in the form of fat wood shavings followed by fine kindling (twigs), then course kindling (bigger twigs), then fuel. Under very wet conditions a greater quantity of finger sized fuel might be needed to ignite the large fuel at the top of the fire. Building the fire on a foundation of wrist thick logs keeps the tinder and fine kindling from absorbing moisture from the ground and provides better ventilation.
Where most people fail at fire building is either they cannot get the reaction to start at all, or they get it started but it stops before building enough thermal ballast (coals) to be tolerant of ham-fistedness or poor fuel. Their domino line is missing pieces or the dominos get too big too fast. The first few minutes are the most crucial because the reaction has very little energy and what energy there is needs to be transferred and directed very carefully. Once a fire has a bed of coals there's enough heat ballast there to compensate somewhat for inferior fuel or poor fuel arrangement.
Even with coals a fire can suffer. A smokey fire is a poorly burning fire. Smoke is the result of incomplete combustion. There's fuel, but not enough oxygen or heat. It's hard to add more heat but you can rearrange the fuel to allow more airflow. That's why people poke the fire...to rearrange the fuel so it burns more efficiently, whether they know it or now
Matches need to be kept dry. A quality match case costs little and will last a lifetime. Click image to see similar models on Amazon. There are a lot of different strategies for being able to get a fire lit. But in order for it to work AND be with you when you need it (you'll never know when that is), it has to be simple, versatile and small enough to fit in a pocket unnoticed. The one system that has never failed me in any environment is a match case filled with storm matches and a sharp knife.
Stormproof matches are readily available from REI (with their brand), though many places cary them under different brands (also known as lifeboat matches) and they're all the same match, near as I can tell. And they're pretty amazing. They burn hot for about 12 seconds and once lit, they don't go out, even if you stick them under water. That 12 seconds of hot flame is enough heat to ignite even course, damp tinder if it's laid right. The downside to the stormproof matches is they require a striking strip...they're not "strike anywhere". Since the strike strip has to be kept dry, it goes in the match case too. When putting the striking strips in the match case, be SURE to have the striking surface away from the matches. Storm matches don't require oxygen to burn, and while I don't know for sure what would happen if a dozen storm matches went off in your pocket, I bet it would leave a mark. Also, the matches need to be replaced every year, so I replace them every six months or so. They do not last indefinitely inside the match case, though you can replace them with matches from the original package so long as it was stored in a cool, dry place. Strike a couple up just to make sure they're still fresh.
Storm matches will burn in wind, rain, even purportedly underwater. Click to buy on Amazon. A very small ferrocerium rod takes the place of one match. What it provides is another way to ignite the matches if the striking tips get compromised, as well as a long-term way of lighting fires if the matches get used up. Ferrocerium rods will chemically react with the matches and turn to powder if not protected. I keep mine wrapped in a piece of aluminum foil, but a coating of fingernail polish works too.
So the match case means I always have a good source of stormproof matches, which is a start. Next step is to prepare tinder and kindling which will readily ignite from that ignition. The technique that has worked for me every single time is to use a knife to make a large pile of shavings and light it with the stormproof match. It's not always the best technique, as many environments have a plethora of natural tinders which are easy to collect and burn ferociously. But if you don't know how to identify and gather that tinder, or it's too dark to find it, or your leg is caught in a bear trap, wood shavings and a match will get you a fire wherever there is a piece of wood to burn.
I'm operating under the theory that everyone caries a knife all the time. I'll frequently forget my wallet, my keys, my phone, and sometimes even shoes, but I doubt I've forgotten to slip a knife into my pocket twice in forty years. I ALWAYS have a knife, or two, or three with me. Not because a knife saved my life back in ‘Nam (wasn't there), or because I think a knife will allow me to thrive after the apocalypse (it won't), or because I'm dangerous like that (I'm not). I always have a knife with me because I love knives... have since I was a toddler. Some folks think that carrying a knife is a thing from yesteryear, but modern plastic packaging has made a knife more valuable than it's ever been. At this point I don't think I could even liberate a peanut or a potato chip without one, much less get into a blister pack. And being a dedicated knife carrier keeps you from flying commercial, which is a bonus in SO many ways...
Most people figure a knife is a knife is a knife, but different knives preform dramatically divergently in regards to cutting wood. While any sharp knife will make shavings, some will do it with a fraction of the effort of others. Because knife philosophy is such a core element of bush craft, we've dedicated an entire forthcoming article to it. Look for that to be add to the Knowledge Base soon.
To show how well this technique works when practiced regularly I started two fires in poor conditions. After a solid week of rain, 2.5 inches in the last 14 hours alone, I set out to light a fire.
|Precipitation:||Raining steady, occasionally hard.|
|Wind:||12 gusting to 24 mph.|
I picked a dead pine that was down, but not all the way on the ground. You could break it, but you had to bend it past 180 degrees to do so. This is NOT a good fuel choice as drier fuel could be found in the area...I just use it to illustrate that even with substandard fuel a good woodsman can still get a fire lit.
I used my knife to shave as much as I could off the top of the tree, staying with a piece that went from about half wrist-thick to thumb thickness at the end.
I put what I thought were the best shavings from deeper in the wood at the bottom and stacked the wetter shavings on top of it. All of the shaving were coarse and wet, both from the condition of the tree and from the rain. The match was also wet from the time it took to photograph it to light it.
One storm match inserted at the bottom of the pile and it lit off. Total time from tree to ignition: nine minutes (not including the picture taking). Note that I left the knots alone and cut around them... carve the easiest wood first and leave the tough bits for when the fire is going well.
From this point I kept shaving down pieces of the tree and feeding the shavings onto the fire. As the fire got larger and the pieces got smaller, I added them and grabbed the next piece. It didn't take long for the fire to shatter the piece of tile I built it on (I was in my front yard, after all). I'm just showing the ignition phase here...had I been building a fire for real I'd of had a supply of fuel and kindling at hand to add to the fire.
Next I picked a soggy, slimy, partly rotten piece of black oak off the ground. Oak is not good tinder by any means, as unlike pine or fir it has no volatile sap and absorbs water more completely, and this piece was really wet with moss and lichens growing on it.
Same drill as before...one oak branch about wrist thickness, one puukko knife, and eight minutes worth of shavings. Note I didn't try to whittle the branch from one end to the other: I picked the easiest sections to shave and left the difficult sections for later.
While I mentioned the time it took me to make the shaving piles, where most people fail in lighting a fire is rushing the job. It can easily take twenty or thirty minutes to collect and prepare enough wood for a fire to sustain itself while you collect more wood. If you need ten minutes worth of shavings to ignite your kindling and you try to light the fire with only five minutes of shavings, you're now fifteen minutes away from a possible fire. Take your time and get it right the first try. Have more tinder than you need, not just what you think is enough. Inherent in that philosophy is you can't wait until you're shivering cold to start making a fire...you need to plan ahead to be successful.
Just like before, I keep shaving down big pieces and adding the shavings till the big pieces are small enough to burn. A couple of these pieces are too large to burn but the fire is hot enough to start drying them out while I put more shavings on. At this point the fire is able to withstand heavier rain or wind and has enough heat to quickly ignite finger-thick wood, even if damp.
Arranging heavier fuel around and above the tinder pile before lighting is fine if you're confident about ignition, but it limits your ability to continue adding shavings and fine kindling during the fragile establishment phase. In this fire the heat from the tinder and kindling is already pre-heating and drying out the larger fuel.
Like everything else, there's more than one right way to light a fire. But this is the only system I've found that is small and light enough that it's always with me in the woods and which will always get a fire lit. And at this point a shaving pile is about the only way I light a fire, regardless of what else might be available. It keeps me in practice and is quick, simple and reliable, and it lets me play with my knives.
There's an old saying: "Red man builds small fire, sits close. White man builds big fire, stands back." Pretty hokey, but it does illustrate that there's more than one way to build your fire.
Fires serve different purposes and are built in different conditions. There are fires for cooking, signaling, taking the chill off during a tea break, or keeping you alive when its your only source of warmth. Each of these fires is going to be built differently.
A small twig fire heats up a kettle of tea and keeps wet backpackers from getting a chill during their break on a saturated day. The biggest fuel used was the thickness of a thumb and the burn patch was about two feet square. While a disastrous place to build a fire in the heat of summer, this is in early spring when the woods are still soaking wet and it's been raining hard for several days. The fire will not travel through the lush vegetation and the short burning duration won't dry out the ground litter. A nearby stream provided water to completely drown the ash pile.
Small twig fires are fast and easy to build and burn out quickly. They rely on high quality fuel of small diameter to keep burning rather than the thermal ballast of a bed of coals. They make ideal cooking and warming fires as they are quick to build and extinguish quickly. The short duration and low heat intensity is much less impacting than a camp fire that burns for hours.
The heat you feel from a fire is only the radiant heat, since the air heated by convection just goes up into the sky. Radiation from the fire goes in all directions: you only benefit from a small portion of the heat the fire generates. The only way to get more heat from a fire without getting so close to risk burns is to either make it larger or to reflect some of the wasted radiant heat back towards yourself with improvised walls. The reflective walls can also provide some shelter from wind, further increasing the warming effect of the fire.
Big fires are necessary in very cold or wet conditions. Wet fuel needs to be preheated and dried to burn, and a large fire will withstand more rain than a small fire. Building large fires when they're not needed is wasteful of resources, unnecessarily damaging to the environment, and increases the risk of a forest fire.
Because radiation decreases with distance, a person sleeping by a fire needs a fire that's as long as they are tall in order to effectively heat their whole body. Building a reflective wall to sleep against will help heat the side of you away from the fire.
In very cold and/or wet conditions you need a larger fire, both for the added heat it provides you and to keep it burning efficiently. It takes a tremendous amount of energy to dry out damp fuel, and a larger fire utilizes wet fuel more efficiently by pre-drying a large enough quantity of fuel to keep the fire burning.
Did you leave your fire DEAD OUT?Most fires are not built in survival situations. They're built for warming, cooking, mosquito control or just sitting around in the evening. It's these "practice fires" that teach us how to get a fire going when our lives depend on it. Make a habit of making your fires with natural tinder and a single match even when newspaper and charcoal lighter fluid is available.
Few things have the same potential for disaster as a match. When you pull the trigger on a gun you own that bullet no matter where it stops or what damage it does. The same is true when you strike a match. Whatever results from that match, you own it.
To be clear, there are places and conditions in which it is simply unsafe to have ANY sort of open fire. Luckily these coenside with environments in which you're really unlikely to need one. There are many more conditions where a fire is warranted, but it will easily spread into a forest fire if mismanaged or left unattended. It should be law that any person abandoning a smoldering campfire can be horsewhipped almost to the point of death by anyone lucky enough to catch him.
Putting a fire out isn't hard, but like lighting one there's a technique to it. First off, where you build your fire will have a huge impact on how easy it is to put out. Fires need to be built on bare mineral soil, not the organic duff made from decomposing forest litter. That duff can be 12" deep in places, and in most conditions it's impossible to build a fire on it and have any assurance of getting it put out when you leave. Wet duff can get dried out and act like a smoldering cigarette, only on a much larger scale. The longer a fire burns, the greater the cigarette effect. So build your fire on mineral soil with a minimum of 12" clearance from the edges of the fire to any sort of organic ground duff.
The easiest way to extinguish a fire is with water, but just pouring water over a fire does not put it out. You have to stir the water into the ashes with a stick, digging down into the heated soil and dissipating all the heat. If you don't have water available or only have a limited amount to work with, plan ahead. Burn only small twigs so there aren't large coals to contend with. The flames should be out an hour before striking camp, and 1/2 hour before leaving camp spread all the ashes and coals out over a larger area so they cool off. Don't bury them with soil, but stir them into the top inch of ground so they cool. Crush any unburnt pieces of charred wood and rub them into the soil. The goal is to make the fire give up it's heat to the ground and air.
How do you know your fire is out? It's the simplest thing in the world...just sift through all the ashes with your bare hand. If it's cool enough to do that and there aren't any hot spots, the fire is out. If you're not happy doing that, then you obviously don't believe you've put the fire out, do you?
Don't build rock circles. They do nothing to contain the fire and act as an ugly reminder of your activity long after the ashes have disappeared. By the same token don't build your fire against a boulder where the smoke will scar it. If you're camping where fire pits already exist, use them rather than scar another piece of real estate. Fastidious woodsmen will, after assuring the fire is dead out, spread the ashes over a still larger area and erase signs of their presence. It might not be a perfect job, but six months later nobody will be able to tell someone already camped there.
Real woodsmen tend to see a fire as something more than just a heat source. Fires are, if not actually sacred, at least a source of enjoyment...a sort of friend. The smoke from pine or aspen or alder wood has a deeply satisfying, pleasant aroma. The smoke from a cardboard beer carton or plastic food package is about as pleasant and enjoyable as drinking someone else's vomit. Burning garbage extremely poor backcountry form. Don't do it.
That said there are times when burning food waste is the only reasonable way to deal with it. Fish bones in grizzly country comes to mind. If you need to burn food waste do it in a hot fire with extra kindling thrown on. Burn it up as quickly an hotly as possible. Even something benign as coffee grounds leave an acrid and revolting stench if allowed to smolder in a fire.
The ability to make a fire under trying conditions is perhaps the single most important skill a woodsman can possess. Its a skill that might save your life in an emergency, and is guaranteed to make your non-emergency life much, much more comfortable. Practicing in poor conditions and at your own convenience (instead of in an emergency) with the above techniques should increase your chances of survival post-crash or during an unplanned overnight situation.