Nutrient Loss From Worm Food

Intriguing question from Carolyn:

Many posters to the various online worm sites mention
draining the liquid from frozen or partially rotted worm food and
feeding the worms only the fiber.

Are sugars, enzymes, vitamins, minerals and microbes lost down the

I would have a tendancy to pour any excess liquid from frozen
produce or from a far along worm food collection pail into a bin of
recently harvested vermicomposts. The liquid food would be very
broken down and ready to eat. The moistue would encourage the eggs
remaining in the vermicastings to hatch. In a few months these worms
too can be harvested.

Hi Carolyn – I don’t think anyone has ever asked me a question like this, but you make a very valid point!

When food wastes (particularly fruit and veggies) are frozen or allowed to rot, the cellular structure of the materials starts to break down, often releasing a fair amount of water all at once. As such, the practice of draining excess liquid off before adding the materials to a worm bin is often not a bad idea at all. This is especially important with enclosed, plastic bins – your ‘typical’ small-scale worm composting bin – since pooling of liquid in the bottom can occur very easily, potentially creating swampy, anaerobic conditions.

I myself don’t ever drain my waste materials – instead, I mix them with a lot of absorbent bedding materials and/or add them to open systems where excess liquid is not a concern . Speaking of which, there are obviously going to be cases where it will be really beneficial to make sure all the liquid remains with the waste materials – such as when you are adding frozen wastes to an outdoor worm bed during the summer. The frozen material will help to cool down the system, and the liquid released will help to add important moisture (which in turn also can help to cool the system if there is adequate air flow).

I guess when it comes down to it, while you likely WOULD lose some nutrients etc, you would still be left with a decent amount of the ‘good stuff’, and since you’d be adding more materials on a fairly regular basis I suspect your worms wouldn’t ever suffer from any sort of nutrient deficiency. Worms certainly grow bigger, faster etc in different waste mixtures – and perhaps those people who consistently drain off liquids will end up with smaller and/or fewer worms over time – but all in all, I think these worms are highly adapted for feeding on all manner of biodegradable ‘waste’ materials.

As far as microbes go, you definitely don’t need to worry about losing them. They reproduce SO quickly that any lost in the drainage liquid will quickly be replaced by new ones growing in the leftover material.

Your idea re: pouring the liquid on to finished vermicompost is interesting. I would definitely only do this if A) I wasn’t adding so much that liquid was draining out of the bottom (since you’d then be losing valuable stuff from the compost), and B) If I was not planning to use the vermicompost anytime soon. You’d definitely want to allow time for everything in the liquid to be stabilized. You mentioned “in a few months”, so I get the feeling my second concern isn’t applicable.

Anyway, I hope this helps. Thanks for bringing up this interesting topic!

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  1. During the summer, I would freeze all of my kitchen scraps. I did not want to generate extra heat. I put the frozen stuff in a bucket, let it thaw to room temp, and throw it in, including the water. I figured the water was part of the waste. This winter I won’t freeze anything so,when I add the kitchen waste, the water from the scraps are going to release into the bin.
    That is what I do.

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