Thanks to reader Lisa, who asked, "We have a
big composter that you load with everything, keeping a mix of browns
and greens, turning it periodically. It's been frozen all winter and
now I'm wondering if it's 'bad.'"
Great question! I put my recently-collected food scraps in the freezer so they don't rot while I wait for my indoor composting redworms to arrive. So I've got frozen compost on the brain, and I've discovered two things abut it that are really exciting:
1. Frozen compost breaks down faster. When food scraps freeze, the water inside them become tiny ice crystals. Ice crystals are sharp, so they break cell walls. That's why frozen blueberries are never firm when you un-thaw them, and it's why frozen bananas make such delicious mush for banana bread. Broken cell walls is what you want for compost--the smaller the matter, the faster it breaks down to its essential organic elements (ie compost).
2. Freezing compost kills fruit fly eggs. Thanks to reader Jenn for pointing this one out! It'll be especially important for me, as I plan to use my compost bin year-round (indoors when it gets too cold for the redworms to be outside). Shoo, fly, don't bother me!
So that's all by way of saying, don't worry about a compost pile that froze over the winter. Like everything else, it will spring back to life in the coming weeks. And who knows - depending on the size of your pile, there might even be a core that's been "cooking" in the center of the pile all winter long!