For those who live in colder climates, composting can seem like a three-season solution - only possible when the ground is soft and the sun is strong (and your inner green-thumb comes alive!)
However, composting can still be a wintertime activity - if you follow a few simple steps!

First Things First: How Does Winter Composting Work?
The most important thing when starting or maintaining a winter compost pile is also one of the most important thing for people during the winter: staying warm.
Compost requires heat and aeration (or "turning") in order to break down organic wastes. During the winter, it's actually recommended that you don't turn your compost pile, as this will allow heat to escape and will slow the breakdown process. It's also recommended that you do not add any additional liquids, as these will freeze and further lower the temperature of the pile.
If sufficiently hot, damp and aerated, your winter compost pile will continue to break down, regardless of outside temperatures. Even if your compost pile freezes or dries out, this won't stop the process, which can easily pick up again in the spring.*
So, the question becomes - how to maintain a decent level of heat in your compost pile during the coldest season of the year?

How Do I Start A Winter Compost Pile?
A winter compost pile requires all the same materials and maintenance that a regular, summertime compost pile requires - plus just a little bit more.
1) Before you start: pick your location wisely
Before you start creating your compost, you're going to need to pick an open space or large bin/tumbler in your yard that is close enough to your door that makes it easy to access in unpleasant weather conditions. Because, let's be real, nobody wants to wade through three feet of snow to reach their compost pile.
2) Collect your "ingredients"
To start a winter compost pile, you'll need:
1 part "green materials" | (minimum) 3 parts "brown materials" **
Because the outside air temperature is considerably colder than the temperature you want to achieve with your compost pile (between 120-170 º F), you're going to want to really stockpile your brown materials in particular before starting your pile (as these become harder to come by once winter sets in). This will ensure that you're always giving the aerobic bacteria in your compost enough carbon-rich materials to feed from and generate that much needed heat!
3) Start layering!
The next step is to start adding your greens and browns to your selected bin or area.
Remembering your ideal brown-to-green ratio is around 3:1, add a layer of browns to the bottom of the pile/bin. Next, add a layer of greens. Continue with your layering until you're out of greens and browns, making sure to always finish with a brown layer: this will ensure that your compost does not attract unwanted pests, or spoil in direct sunlight. It will also help keep in the heat!
4) Keep it warm!
If you're using a bin in which to store your soon-to-be-compost, it'll be easy enough to wrap it up in cardboard or a thick blanket.
If you're using a compost pile, you might be safe in leaving the pile as is: the outer layers will insulate the inner layers and allow it to keep breaking down.
Another thing you can do to speed up the heat-up process is by cutting up your food scraps and your brown materials prior to adding them to the pile. Smaller pieces break down faster as they allow oxygen to reach a greater surface area.

Maintaining A Winter Compost Pile
If your compost pile is set up with the proper ratio, you should have no issues by simply continuing what you've been doing (layering and ensuring the pile/bin stays warm enough).
If you're noticing that something seems off (funny smells, flies, or that the pile doesn't seem like it's doing anything at all after a few months), then you can try a few simple tips n' tricks:
Final Thoughts
Winter composting is as rewarding as regular composting - it just might take a little bit longer, and require more patience, and a few additional steps to keep it happily decomposing your waste.
As always, composting is an incredibly rewarding experience. It's an inexact science, which means that getting into the rhythm of your compost pile is absolutely essential.
The benefits of compost are myriad. However, sometimes a traditional compost pile is not possible for folks, given their living situation and/or lifestyle.
13 Reasons Why You Need An Electric Composter This Year
That's why we're going to write an article about Winter Composting with a FoodCycler to help you out if you're short on time, space, physical ability or know-how! Stay tuned!
* If your winter composting system freezes: don't panic! The constant freeze-and-thaw of the pile is actually good for the pile, as it weakens the structural integrity of the fibres holding the various brown and green materials together.
** There are a bunch of different ratio recommendations for the ideal green-to-brown mix, but the best indicator of a successful ratio is the success of your compost pile! To start, we recommend trying at least 2 times as much brown matter to green matter, and seeing where that gets you.