No matter how particular you are about building your compost pile properly in winter, not much will happen in the cold weather. Mounds of old salad, cooked broccoli, and moldy bread just sit there. There won’t be odors from the pile in winter, but it’s not a pretty sight and may attract animals.One way to bypass problems with composting kitchen scraps in winter is to do it indoors. To compost indoors, or at least to get materials started composting, all you need is three buckets with loose-fitting lids. (Five-gallon plastic buckets, which are readily available from restaurants, often at no charge, should suffice.) If the lids fit tightly, just keep them loose as you fill the buckets with compost.
First, fill bucket #1 with a mixture of equal parts of dry sawdust or peat moss and dry soil, with a little limestone added. Do not use sawdust from pressure-treated or painted wood.
Then, on the bottom of bucket #2, lay an inch of dry straw, leaves, or shredded newspaper. Dump your kitchen scraps into bucket #2 as they become available, each time sprinkling on some of the sawdust-soil mixture from bucket #1 to absorb odors and excess moisture. The sawdust-soil mix also adds carbon to the compost-in-progress, which balances out the high nitrogen concentration in most food scraps. If you have a lot of scraps at once, dump in a portion at a time, covering each layer with the sawdust-soil mixture. Chop up large pieces of scraps and let water drain from anything that is very wet before tossing it into the bucket.
When bucket #2 is full, set it in a warm spot indoors and start filling bucket #3. By the time bucket #3 is full, the contents of bucket #2 should be well on the way to becoming compost, that is, no longer looking like garbage and no longer attractive to scavengers.
When buckets #2 and #3 are full, you can dump the contents of bucket #2 outside on your compost pile. Then start filling that bucket again while bucket #3 sits. I keep the bucket I am filling and the sawdust-soil mixture right in my kitchen. Warmth hastens decomposition, and the whole setup is odor- and fly-free, environmentally sound, and very convenient.