Vermicomposting Commercial Kombucha Brewery Waste

Updated: Jun 23

What is Vermicomposting?

Vermicomposting is composting with worms. In our case, red wigglers. These worms will eat almost anything that at one point grew out of the grown, including our tea leaves, fruit, SCOBY, cardboard, paper and turn it into worm castings – known as black gold amongst gardeners. The worm castings can be used as organic fertilizer teeming with beneficial microbes that also defend against fungal disease. Or it can be mixed with water to create worm casting tea, to water your plants with.

There is so much to discuss about worms, worms’ castings, composting, and how to do it effectively, but what this article will focus on is the efficacy of using red wigglers to dispose of our kombucha breweries waste.

Logistical Considerations

Is it possible?

Firstly, let us determine if it is even possible to use red wigglers to compost our kombucha brewery waste. Red wigglers require a balanced diet of nitrogen rich foods, and carbon rich foods. Nitrogen rich food includes fruits and greens. Carbon rich foods are materials like paper and cardboard. Our organic waste includes:

  • Tea leaves

  • Various fruits

  • Herbs

  • Ginger roots (?)

  • SCOBY (?)

We can be sure that the red wiggler will devour the tea, fruits, and herbs, but we are not so sure about the ginger roots or SCOBY. Red wigglers do not like irritable foods like ginger roots, garlic, or onions. As for the SCOBY, it is mostly made of cellulose which the worms should eat, but the acidity could be dangerously low. Red wigglers prefer a neutral pH of 6-7, while our SCOBY could be as low as 2.8 pH. In fact, our spent fruits will likely have a 3-3.5 pH since they are all soaked in our kombucha.

We can address these potential problems by disposing of the ginger roots separately and adding a pH balancer like crushed eggshells or limestone to neutralize the SCOBY and fruits.

In addition to the organic fibres, we will have to add lots of carbon rich bedding material, such as cardboard and paper. Because most of our compost additions will be water saturated, we will need amble dry bedding material to avoid overwatering our worms. It is safe to assume that we will have enough dry bedding material to supplement our nitrogen rich foods, from all the different shipments and paper we receive and use.

My conclusion is that with generous dry bedding addition, the use of a pH balancer like limestone and the exclusion of ginger roots, our brewery should be able to produce waste materials that would be ideal for vermicomposting.

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