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

When someone says a product is “new and improved,” it’s wise to take it with a grain of salt. But with Mill’s redesigned food waste bin, you can believe it.

As before, the bin accepts a wide variety of food waste—only a handful of items, such as oyster shells are off limits—and grinds and dries them into a consistency that resembles coarse coffee grounds. These soils can be mixed with garden soil, spread on lawns or even sent back Mill, which then offers it to farmers as chicken feed. A household using the bin can expect to reduce around half a tonne of greenhouse gas emissions per year.

So what’s different? Almost everything.

Where the old bin worked as promised, it wasn’t always as quiet or fast as I’d like, sometimes taking nearly a day to complete a cycle of drying and grinding the food. That’s not the case with the new one, which I’ve spent the last two weeks testing. Every night at 10pm, my bin would start a cycle and by the time I woke up, it was always done, just as co-founder Matt Rogers promised me. In addition, it is significantly quieter, no longer disrupting evening TV viewing.

Here’s how Mill did it.

The design plan was simple, said Kristen Virdone, head of product at Mill: each cycle had to be completed before breakfast. With that guide and a year’s worth of data, the team dug in.

From the outside, the new Mill bin doesn’t look that different. The visual changes are so subtle that you have to pay close attention to notice them, like when automakers tweak a model’s headlights to freshen up the look. Probably the biggest cosmetic change is the fact that the status lights no longer shine through the wood grain plastic lid, a smart piece of technology that I miss.

Under the hood, one of the biggest changes users will notice is that the augers that grind 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 screws to sweep. It also helped eliminate unpleasant noises. Previously, the snails dragged food scraps along the curved bottom, creating what the Mill team calls “haunted house noises.” (To me, it always sounded like a creaking, groaning pirate ship.) The new configuration exorcised those demons.

The vertical layout also gave the design team the opportunity to add small paddles to the tops that users can twist to help dislodge soils when emptying the bin.

The bucket itself is now made entirely of metal. The previous one had some plastic parts, which reduced the amount of heat that could be transferred from the heating element to the food scraps, lengthening drying times. To help the soil slide out, the bin is lined with a PFAS/PFOA free ceramic coating.

To further reduce cycle times, Mill’s team was able to use machine learning algorithms trained on data collected over the past year, Virdone said. As a result, the new software is smarter about how long it takes to run each cycle.

Each bucket also has a suite of sensors, just like the previous version, although now the team has enough data to differentiate the weight of one strawberry from four raspberries, said Suzy Sammons, the Mill’s chief communications officer. Two humidity sensors, one on the air inlet and one on the exhaust, help the bin know exactly how long it takes to run each drying cycle.

“If you think about it, there are infinite combinations of food that can go into our bins,” Virdone said. “Having a year under our belt and having real families make real weird food combinations, we’re starting to see the limits of what’s out there.”

The fans have also been completely redesigned, Virdone told TechCrunch. They are quieter and their position within the bin has been revised to minimize the amount of noise escaping the unit. Overall, the changes worked well. The fan noise of the new unit was significantly reduced during my testing.

The only thing I noticed missing from the new bin is a power-activated lid. On the old model, pressing the foot pedal would mean a motor quickly raised the lid. It was surprisingly satisfying to use, and my kids loved it too. The new one is a more traditional link-operated lid that’s physically attached to the pedal, like a stereotypical kitchen trash can. Virdone said user testing revealed people preferred the mechanical lid, saying it was more intuitive than the motorized version.

Like the old bin, the new one requires an outlet nearby. In our house, that means the bin technically lives in the family room, just a few steps away from the kitchen sink. It works fine in practice, although it looks a little out of place when sitting on the couch. If I were going to make him a permanent home, I’d like to find him a home somewhere in the kitchen, perhaps adding another outlet in the process.

Other than that, the only thing holding me back from buying one is the price. At $360 a year, it’s not cheap, especially compared to the unsubsidized composting service in my town, which is a third of the cost. The new Mill price is about 10% cheaper than before, provided you have somewhere to dump the ground. If you don’t, you’ll have to add $10 a month to pick it up. It is possible that the price will be reduced if Mill is able to negotiate subsidies through the municipalities. Currently, the only cities that have agreements with Mill are Pittsburgh and Tacoma, Washington.

Given the current cost, the Mill’s bin still isn’t for everyone. However, for households that don’t have composting services available or don’t like the smell that comes with it, it’s a great product made even better.