Freezing food waste is a really interesting technique for managing both the quantity and the quality of the food source you are feeding your worm bin. This short article looks into 3 reasons why you should freeze food waste for vermicomposting and 2 reasons why you shouldn't.
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3 Reasons to Freeze Food Waste
Excellent way to preserve food waste for when you need it
You probably know that the worms's capacity for processing our household waste can vary with changing temperatures, humidity, even barometric pressure for those of you “lucky” enough to have received Indian Blues instead of Red Wigglers. And you're probably not creating the same amount of food waste each week.
Freezing household waste for a rainy day allows you to stockpile some worm food in reserve without fear of attracting odors, flies, or pests.
Frozen Food Decomposes More Quickly
Once thawed, previously frozen food will break down faster than food that hasn't been given the “Han Solo” treatment. As our food waste is high in water content and because water expands as it freezes, freezing food waste will rupture the cell walls in your food waste.
So once the food thaws, it will decompose faster, making itself more available to your microbes and worms.
Freezing Kills Fruit Fly Larvae
It's no surprise that fruit wastes will attract fruit flies. And certain wastes like banana peels are notoriously good hosts for tiny fruit fly larvae. This is why vermicomposters can be surprised by the presence of fruit flies that fly out of their bin when it sure seemed like fly-less waste went in.
By freezing your food waste, you can help control the introduction of fruit flies and their eggs into your worm bin.
Why Not to Freeze Food Waste
I think “wasteful” is probably too strong of a word, but expending energy to freeze food waste that you intend to feed to worms just a few days later may go against the minimalist, zero waste mindset that lots of vermicomposters admirably strive for.
The spent BTUs to freeze your waste may be considered an unnecessary step in the process that adds cost, complexity, and a greater carbon footprint.
One other issue is that thawing food waste releases water very quickly. The expansion of water as it freezes ruptures those cell walls, ultimately allowing a rapid escape of water when the food waste warms up. I am constantly pounding the table about how most vermicomposters run their worm bins way too wet.
My Thoughts: To Freeze or Not to Freeze?
I'm totally agnostic on the matter. Personally, I am a lazy vermicomposter and resist extra steps in the worm composting process. My normally method of food waste collection is to place an uncovered 5-gallon bucket outside the back door and simply toss in whatever I plan to send to the bin.
This doesn't come with downsides though!
Heavy rains can partially fill my bucket with water. Squirrels are plenty interested in what I put in there. The food waste can start rotting, And fruit flies and other insects can appear.
But so long as I add dry bedding to soak up the moisture and wring it out before adding it to the bin, all of the above problems go away within a couple days of adding the waste to my Urban Worm Bag.
As a general matter, I don't tell people they should freeze waste, and I totally get the anti-zero waste aspects of it. But the reasons to do it can be pretty compelling! If you can preserve food waste for when you need it AND speed up its eventual decomposition, then freezing isn't a bad way to go.
Tell me your story. Are you freezing or not?