Mill’s redesigned food waste bin really is 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 like oyster shells are off limits — and grinds and dries it to a consistency that looks like chunky coffee grounds. Those grounds can be mixed with garden soil, spread on lawns, or even shipped back to Mill, which then offers it to farmers as chicken feed. A household using the bin can expect to trim about half a ton of greenhouse gas emissions annually.

So what’s different? Just about everything.

Where the old bin worked as promised, it wasn’t always as quiet or fast as I would have liked, 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 couple weeks testing. Every night at 10 pm, my bin started a cycle, and by the time I woke up, it was always finished, just as co-founder Matt Rogers promised me. What’s more, it’s significantly quieter, no longer disrupting evening TV viewing.

Here’s how Mill made it happen.

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

From the outside, the new Mill bin doesn’t look that different. The visual changes are so subtle you’d have to be paying close attention to notice them, like when automakers tweak a model’s headlights to freshen the appearance. Probably the biggest aesthetic change is the fact that the status lights no longer shine through the wood-grain plastic lid, a nifty bit of shy tech that I kind of miss.

Under the lid, one of the biggest changes users will notice is that the augers that grind the waste are now vertical instead of horizontal. That change allowed the team to make the bottom of the bucket flat instead of rounded, making it easier for the augers to sweep clear. It also helped eliminate untoward noises. Previously, the augers would drag food waste across the curved bottom, creating what the Mill team calls “haunted house noises.” (To me, it always sounded like a creaking and groaning pirate ship.) The new configuration exorcized those demons. 

The vertical arrangement also gave the design team an opportunity to add little paddles to the tops that users can twist to help dislodge grounds when they’re emptying the bucket.

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

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

Each bin also has a suite of sensors, just like the previous version, though now the team has enough data that it can differentiate between the weight of one strawberry and four raspberries, said Suzy Sammons, Mill’s head of communications. Two humidity sensors, one on the air inlet and one on the exhaust, help the bin to understand exactly how long each drying cycle needs to run.

“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 put in real weird combinations of foods, we start to see the bounds of what’s in there.”

The fans have been completely redesigned, too, Virdone told TechCrunch. They’re quieter, and their location within the bin was rethought with an eye toward minimizing the amount of noise that escapes the unit. In aggregate, the changes worked well. The new unit’s fan noise 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, stepping on the foot pedal would signal a motor to swiftly lift 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’s physically connected to the pedal, like a stereotypical kitchen garbage bin. Virdone said that user testing revealed that people preferred the mechanical lid, saying it was more intuitive than the motorized version. 

Like the old bin, the new one requires a power 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 out just fine in practice, though it looks a bit out of place when you’re sitting on the couch. If I were going to make a permanent home for it, I’d want to find it a home somewhere in the kitchen, maybe adding another outlet in the process.

Apart from that, the only thing that’s preventing me from buying one is the price. At $360 per year, it’s not cheap, especially compared with the unsubsidized curbside compost service in my city, which is a third the cost. Mill’s new price is about 10% cheaper than before, provided you have somewhere to dump the grounds. If you don’t, you’ll have to add $10 per month to get it picked up. It’s possible the price will come down if Mill is able to negotiate subsidies through municipalities. Currently, the only cities that have deals with Mill are Pittsburgh and Tacoma, Washington..

Given the current cost, Mill’s bin still isn’t for everyone. But for households who don’t have curbside composting services available, or that don’t like the smell that accompanies them, it’s a great product that’s gotten even better.