Urban Worm Bag v2.0

This is a review of the Urban Worm Bag v2.0 (UWB). I previously reviewed the no longer available Worm Inn and the UWB is the next generation continuous flow through bag system. Full disclosure, I currently offer this product for purchase.

I’ll start right off the bat and state that the UWB is my preferred vermicompost system that I have used. There is a similar product called the VermiBag, which appears to be at the same level as the UWB but I have not used any of the VermiBag systems myself.

The UWB was designed by Steve Churchill of the Urban Worm Company. The system is an improved version of its predecessor the Worm Inn. The UWB also comes with a metal stand and corner pieces so there is no additional purchase requirement to get the system up and running.

The UWB has a surprisingly large vermicompost area. The system itself is roughly 2’W X 2’L X 2.5’H. The system can fit comfortably in a basement or under a stairway. However, it can easily hold 100 pounds worth of material.

Improvements from the Worm Inn

  • The fabric of the UWB is made from Oxford 900D polyester which retains moisture far better than the Worm Inn’s fabric
  • Metal stand – the UWB comes with the metal stand and corner pieces. The Worm Inn required you to purchase additional materials to build your own stand. The stand can also hold over 100 pounds of material.
  • Improved durability with hanging loops – the loops of the UWB cover about 75% of the top portion of the stand. This spreads out the weight stress over a greater surface area. The Worm Inn’s loops were only about 1″ wide. This improvement not only improves the durability of the system but makes it steadier on the stand. The Worm Inn would often sway when harvesting, but the UWB does not have this issue.
  • Continuous improvement – Steve has updated the UWB several times and the latest improvement is the removable bottom layer. The previous version used a zippered bottom that contained the drawstring. The zipper had a tendency to clog up with material and could get in the way while harvesting. The updated version uses clips and be completely removed.

Moisture retention

The UWB holds moisture much better than the Worm Inn. Now I will point out that the breathability of the Worm Inn was a major bonus. The UWB doesn’t have nearly as much airflow but it also doesn’t require supplemental water added to it like the Worm Inn does. Personally, I wish the UWB had a bit more breathability but I do like the fact I don’t have to monitor the system for moisture as much.

The UWB does run drier that a plastic tote system but I do find that when harvesting it does need a drying period. The Worm Inn on the other hand did not require any sort of drying period.

One major benefit to the increased moisture retention is that the worms travel around the entire system. The Worm Inn needed its moisture to be in the “sweet spot” where it was primarily in the center of the system. The outer layers tended to dry out very quickly and the worms wouldn’t process that material. In the UWB the outer layers are processed just as well as the center.

Harvesting Vermicast

These photos were taken after pulling material from each system. It is hard to see but the vermicast from the Worm Inn is drier than the UWB.

Since the UWB holds more moisture compared to the Worm Inn, harvesting is a bit messier. The vermicast tends to be moister and is often full of worms. Another thing that tends to happen, is that since the material is moist, it can create a condition where the upper layer can collapse. This occurs because the outer layers hold together quite well and don’t slide down, creating a “hole” at the bottom. To prevent this from occurring, make sure to pull down the material along the outer layers. After removing the vermicast, the material will require a short drying period if you plan on screening.

The Worm Inn tends to be easier to harvest than the UWB. The vermicast is drier and doesn’t require as much work getting the material out. Once the material is out, it can be screened right away and doesn’t need a drying period. I should mention that I’m referring to using a 1/8″ screen. Both can be screened immediately using a 1/4″ screen.

Is there a difference in the final vermicast? I honestly don’t have an answer to this. I tend to think that since the UWB’s vermicast is moister, that it would have more microbes and be a better end product. However, the vermicast from the Worm Inn can be re-hydrated fairly easily and the microbes can recolonize the material quickly.

UWB vs plastic totes

The comparison to just the Worm Inn isn’t entirely fair since the Worm Inn can no longer be purchased. The most common vermicompost system is the simple plastic tote.

Advantages of UWB vs plastic totes

  • Better airflow – although the UWB doesn’t breathe as well as a Worm Inn, it is still far superior than a plastic tote
  • Processes food scraps quicker – the improved airflow allows for the aerobic microbes to break down food scraps quickly. In a typical plastic tote, the scraps just tend to take longer.
  • The moisture level is much better and doesn’t lead to “sticky” or “muddy” vermicast.
  • Easier harvesting – the UWB is far easier to harvest vermicast compared to tote systems due to the system just being drier and typically doesn’t have muddy vermicast
  • Fewer other critters – although I’m actually in favor of having additional critters like isopods and springtails, the UWB just generally has fewer critters than tote systems
    • The one critter than I tend to find problematic in tote systems is mites. Most of the time I do not mind them but in smaller totes I have had them climb up my arm when trying to feed or check in on the system. I have never experienced this with the UWB or Worm Inn

I should also mention that I may run my system differently than others. I tend to add food scraps weekly or sometimes more often. The UWB and Worm Inn tend to be better with more maintenance. A tote system on the other hand is excellent for a batch type feeding. Mark Paine’s vernmenting systems use the batch feeding process quite successfully using 5-6 gallon buckets. Tote systems can be used in a similar fashion quite successfully. A batch feeding process is where all the food scraps are added at one time and harvested all at once about 2 months later. The UWB and Worm Inn are not suitable for batch feeding as they can dry out.

Is the UWB a good system for you?

Everyone’s situation is slightly different and the UWB may not be suitable for you. Here are a few conditions that the UWB may not be appropriate:

  • Cost – the UWB is way more costly than a tote system
  • Space – Tote systems come in various sizes and can be placed almost anywhere
  • Maintenance – the UWB requires more regular maintenance than a typical tote
  • Quantity of scraps – the UWB is a large system and can handle scraps from a family of four. If you don’t produce a lot of scraps, a smaller tote system or multiple totes may work out better

Personally, I find the UWB to be one of the easiest and best vermicomposting systems. Food scraps are processed more quickly, can feed about twice as often, easier harvesting and screening, and better airflow are just some reasons that I prefer the UWB to a tote system. In my opinion, the UWB was well worth the cost and I highly recommend it.

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