|Winter food plan!|
Luckily, you don't have to change a whole lot with your foods, but you probably want to make a few tweaks (besides maybe bring a little extra). You want fatty foods! I'll add olive oil to any hot meals I make (and sometimes cold ones). 1 ounce of olive oil is roughly 100 calories, so you can get some bonus energy in measurable amounts easily. But also, fatty foods (besides helping you feel more full longer) keep you warmer as they digest. This is especially important to think about before burrowing into your sleeping bag.
Sitting still in your bag, you no longer have the advantage of creating heat from moving. But you can give yourself a boost by eating plenty of fat right before bed. Dark chocolate is great (Ritter makes my favorite backpacking chocolate). As it burns and digests while you sleep, you will keep cranking out the BTUs throughout the night. I'll also keep a few chunks handy for when the temperature drops more (usually between 2 and 3am), or I just wake up feeling cold in the middle of night. Also, just having a hot meal (and drinks) in your belly is a huge moral boost. Winter isn't a time I would recommend trying to go stove-less!
You also should consider keeping your snack foods (the stuff you want to munch on while hiking) close to your body. Nothing worse than trying to bite into your favorite food bar only to find it frozen solid.
Speaking of stoves - do you need to buy a fancy stove, just for winter? I'll give an ambiguous maybe. It all depends on the temperature, and also on what conditions you are in for. Will you be able to access liquid water, or will you have to melt snow and ice?
Let's start with the affects of freezing cold on stoves. You will encounter a wide range of opinions and experiences with various fuel types in winter. The two most common types you'll see on the trail (in 3 season backpacking) are of course isobutane and alcohol. How do they fare in winter?
I read a very comprehensive article on iso-butane canister stove tests at various altitudes and temperatures, but alas, I can't seem to find it now. I'll just summarize the highlights here.
Quite simply, those canisters are filled with a mix of butane and propane in liquid form. Your canister stove works by burning the gaseous form of those fuels. So in order for your stove to work, the temperature of the fuel inside has to be at or above the boiling point for each (which is a little under freezing for butane, and about -40F for propane).
So essentially, if you take your canister stove out and fire it up in temps well below freezing, you will be burning more propane fuel, and little or none of the butane. It will be harder to light, burn less efficiently, and you'll also end up with a half used canister that you can't burn anymore and have to carry around the rest of your trip. Plus, as the canister fuel is consumed, it will cool off even more, compounding the problem - the rate of butane fuel being used will go down steadily.
So, do you abandon your beloved canister stove for the duration of winter? Not necessarily. You just need to keep your fuel above freezing! Burying it deep down in your pack with your down helps keep the chill at bay, or you can stuff it inside your jacket to warm it up before dinner. You can also submerge it in water if you are really desperate (at worst that will keep the canister above the freezing point). I've even read about people heating up the canisters with another stove or other means. Not sure I can recommend that!
Long story short for canister stoves, you can still use them, but you might need to do a little more work. Also, a good wind-screen is critical to try and regain some efficiency in winter.
|The glory of frosted beards.|
But luckily, you can overcome this even more easily. As soon as I stop and start setting up camp, I'll throw my fuel bottle in my jacket. A small bottle of alcohol is much easier to warm this way then a large fuel canister. Usually by the time I'm ready to make dinner, it's good to go - and I can light it with my striker just like normal. Assuming my finger dexterity is intact anyway.
If that won't work (or I just forgot to keep my fuel warm, or I can't feel my fingers) - I cheat. I fill my can-stove like normal then pull out my storm-proof matches, light it and drop it right in. That ignites it every time, and usually gets the fuel immediately boiling as a bonus. Despite the numerous myths out there, I've used my Caldera Cone setup with alcohol stove well below zero. A good windscreen, again, is a must. A piece of foil or thin metal sheet under the stove also helps tremendously, especially on snow.
So, typically, I would say you are fine with whatever stove you have, assuming you go in prepared and ready to overcome the chill. But besides just boiling water for your meal-in-a-bag (and making hot drinks!), if you want to go into deep winter, sooner or later you may need to melt snow.
What's awesome is, the winter sometimes opens up territories that might otherwise be bone dry any other time of the year by providing an abundance of water everywhere you look. You just need to make it liquid again.
|Turning hail into breakfast at a dry camp in the Tetons.|
I'd be remiss if I didn't mention two other types of stoves that are meant for deep winter. Both liquid burning - so they need priming and a bit more care. But they will be stable regardless of temperatures. Personally, I think you'd have to be in for a lot of winter backpacking to make the investment worth it (I still don't own either type below).
Inverted canister stoves, like the Jetboil Helios, are handy in that they use the same isobutane canisters as most other backpacking stoves. The differences being this one is configured to burn liquid fuel, and uses the canisters upside down. Just like that, the cold isn't a problem!
Whisperlite. The great advantage of these is just how much burn time you can get from one canister - they last a LONG time. You will see reviews and comments are both sides for these stoves. Many love them, but most will agree they need more work and maintenance to keep them working properly. Make sure you are versed in troubleshooting and that it's running smoothly before heading out!
UPDATE: MSR also makes an inverted canister stove that is a bit more affordable, and simple then the Jetboil version: MSR Wind Pro II
Obviously, both these setups are way bulkier and heavier than you would ever consider on a 3 season backpack. But sometimes in winter, heavy loads are the only choice. Of course, you can always build a nice fire (a fantastic treat in winter!), but that isn't always an option. Wood could be scarce, or just hard to find - or fires could be outright banned as it is in most National Parks.
|Frozen lake walking.|
Most people will abandon their water bladder hydration systems for winter. While you can use them, it takes some extra work. You have to remember to blow out your hydro-tube every single time you finishing taking a drink. Forget once, and it freezes up. You are done. You'll also need to keep the bladder against your back. Depending on your pack, that might not be possible.
I switch to winter specific bottles when temperatures plummet, or use home-made bottle insulators (out of Reflectix). By far, I would most recommend the 40oz HydroFlask for winter. It has a vacuum sealed chamber to insulated the inner container, and works wonders for keeping your water from freezing. It can also keep a hot drink hot!
But before you worry too much about buying more stuff, the number one simple way to keep your water liquid is just to keep it next to your body. With your pack hip-belt clipped, there is a natural pouch formed right at your belly that makes a great place to stash your water bottle inside your layers. Heavy winter parkas will usually come with inner pockets designed for just this purpose as well.
In winter, I tend not to carry a whole lot of water at one time (ok, I don't really carry a lot in 3 seasons either!). If you really don't want your water to freeze, well, just carry it in your body! Stay well hydrated at all times. This is especially important in frigid climates, as you will be burning through fluids faster than you realize. If you start - and stay - hydrated, you can probably get away with just 1 liter or so carried at a time. And that's a lot easier to manage then trying to keep several liters from freezing.
This of course assumes you can readily access unfrozen water to refill when you need it. Melting on the go will really slow you down. Plan ahead, always!
Until next time! Be safe out there.