Mill's redesigned food waste bin is actually faster and quieter than before


When someone says a product is “new and improved,” you should take it with a grain of salt. But with Mills' redesigned food waste bin, you can believe it.

As before, the bin takes a variety of food waste – only a handful of things like oyster shells are off-limits – and grinds and dries them to a consistency that looks like coarse coffee grounds. This can be mixed with garden soil, spread on lawns or even sent back to Mill, which then offers it to farmers as chicken feed. A household using the bin can expect to save around half a tonne of greenhouse gas emissions annually.

So what's different? Pretty much everything.

While the old container worked as promised, it wasn't always as quiet or fast as I would have liked. Sometimes it would take nearly a day to complete a drying and grinding cycle. That's not the case with the new container I've been testing over the past few weeks. Every night at 10pm, my container started a cycle, and when I woke up, it was always finished, just as co-founder Matt Rogers promised me. It's also noticeably quieter and doesn't interfere with evening TV watching.

That's how Mill did it.

The design brief was simple, said Kristen Virdone, product manager at Mill: Each cycle had to be completed before breakfast. With that guide and a year's worth of data in hand, the team got to work.

The mill’s organic waste container is closed.The mill’s organic waste container is closed.

The lid has been redesigned and now features a recess for the lock button and status lights, which have been relocated to the base.

From the outside, the new Mill bin doesn't look much different. The visual changes are so subtle that you have to look closely to notice them, like when automakers tweak a model's headlights to freshen up the look. Probably the biggest aesthetic change is the fact that the status lights no longer shine through the wood-fiber plastic lid, a nifty piece of shy engineering that I kind of miss.

One of the biggest changes users will notice under the lid is that the augers that grind up the waste are now vertical instead of horizontal. This change allowed the team to make the bottom of the bucket flat instead of rounded, making it easier for the augers to sweep the waste free. This also helped eliminate unwanted noise. Previously, the augers dragged the food scraps across the curved bottom, creating what the Mill team calls “haunted house noises.” (To me, it always sounded like a pirate ship creaking and groaning.) The new configuration exorcised those demons.

The vertical layout also gave the design team the opportunity to add small paddles to the top that users can rotate to loosen coffee grounds when emptying the bucket.

The bucket itself is now made entirely of metal. The previous bucket had some plastic parts that reduced heat transfer from the heating element to the food waste and increased drying times. To help the waste slide out more easily, the bucket is lined with a PFAS/PFOA-free ceramic coating.

Mill's organic waste bin is open and filled with coffee grounds.Mill's organic waste bin is open and filled with coffee grounds.

New vertically aligned augers provide quieter grinding of food and allow for the addition of small paddles on the top that can be rotated to release the grinding set when emptying.

To further reduce cycle times, the Mill team was able to use machine learning algorithms trained on data collected over the past year, Virdone said, which helps the new software better understand how long each cycle needs to run.

Each bin has a series of sensors like the previous version, but now the team has enough data to distinguish between the weight of one strawberry and four raspberries, says Suzy Sammons, director of communications at Mill. Two humidity sensors, one at the air inlet and one at the outlet, help the bin know exactly how long each drying cycle needs to run.

“If you think about it, there are endless combinations of foods that can go into our garbage cans,” Virdone said. “After having a year of experience and having real families throw in really strange food combinations, we're starting to realize what's in there.”

The fans have also been completely redesigned, Virdone told TechCrunch. They are quieter and their position in the chassis has been rethought with the goal of minimizing the amount of noise coming out of the device. Overall, the changes have worked well. The fan noise on the new device was significantly reduced during my testing.

The only thing I noticed about the new trash can is an electrically operated lid. With the old model, stepping on the foot pedal triggered a motor that quickly raised the lid. It was oddly satisfying to use, and my kids loved it too. The new one is a more traditional linkage-operated lid that is physically connected to the pedal, like a typical kitchen trash can. Virdone said user testing showed people preferred the mechanical lid, saying it was more intuitive than the motorized version.

Like the old trash can, the new one needs a nearby electrical outlet. In our house, that means the trash can is technically in the living room, just a few steps from the kitchen sink. In practice, that works well, although it looks a little out of place when sitting on the couch. If I were to give it a permanent home, I'd want to put it somewhere in the kitchen, perhaps adding another electrical outlet in the process.

Other than that, the price is the only thing keeping me from buying it. At $360 a year, it's not cheap, especially compared to the unsubsidized compost service in my city, which costs a third. Mill's new price is about 10% cheaper than before, assuming you have a place to dispose of the coffee grounds. If not, you'll have to pay an extra $10 a month to have them picked up. It's possible the price will drop if Mill can negotiate subsidies with municipalities. Currently, Pittsburgh and Tacoma, Washington, are the only cities that have contracts with Mill.

Given the current cost, Mills' bin still isn't for everyone. But for households that don't have curbside composting or don't like the smell associated with it, it's a great product that's gotten even better.