Mill Kitchen Bin review: trying to save the planet and feed the chickens

At around 1AM on Sunday morning, my partner sat bolt upright in bed and whispered urgently, “There’s someone in the kitchen!” After listening sleepily for a few seconds to the muffled clunking noise, I replied, “No, there’s not; that’s just the smart bin eating an avocado pit.” 

For most couples, this would have necessitated a further middle-of-the-night conversation, but for my long-suffering spouse, the word “smart” was all he needed to hear to roll his eyes and huffily go back to sleep. 

The noise-making contraption was the Mill Kitchen Bin — a full-sized, sleek-looking Wi-Fi-connected trash can packed with sensors and an industrial-grade food grinder. It had hit a snag (a large pit) during its otherwise quiet nightly business of munching through its load of melon rinds, egg shells, coffee grinds, half-eaten peanut butter sandwiches, and chicken bones. Over nine hours or so, it worked on shredding, shrinking, drying, and dehydrating the food remnants we’d thrown in the 27-inch-tall, 16-inch-wide bin during the day, turning them into “food grounds” by morning. 

The concept here is similar to the electric countertop “composters” you may have heard of — electronic gadgets that grind, dry, and dehydrate uneaten food. But instead of attempting to turn it into compost intended for your garden or houseplants, as those composters do, Mill wants you to ship the food grounds it regurgitates back to the company every month or so, where it turns it into food for chickens.

At least, that’s the plan. Mill CEO and co-founder Matt Rogers tells me they’re still working through some “R&D and regulatory processes” for the feed part. But the idea is that “Food is much more valuable than compost,” he says. “We should keep food as food.”

He’s not wrong. As with Roger’s prior efforts (which include the category-defining Nest Learning Thermostat), the Mill is designed to tackle a huge climate issue. This time, it’s household food waste instead of household energy use. “It’s a massive problem. We throw away about 40 percent of the food we grow, half of which comes from us at home,” he says. 

Consequently, food is the most common item in landfills, where it gives off the greenhouse gas methane as it decomposes. It’s a big, little-discussed, global problem, which is a wildly massive issue to tackle with a pricey smart kitchen bin. “It’s this perfect blend of technology meets design meets climate,” says Rogers of the new invention. Mill provides an alternative if you don’t have the time, space, or expertise to manage a compost bin, or if you have all of the above but have nowhere useful to use the compost. 

I’ve spent a few months with the Mill in my kitchen, and while there is good tech and design here, the bin in its current form is not the solution to food waste. What it is is a very expensive smart rubbish bin that will make you feel better if you can’t / won’t compost or are unable to make any other effort to reduce what you throw out. 

You can’t buy the bin outright. Instead, it’s a subscription model, so you’re basically renting it. You either pay $396 a year ($33 a month) or $45 monthly plus a $75 bin delivery (for a total of $615 for the first year). If you reserve a Mill bin today, Mill tells me it should be shipped to you in about two months. There’s no minimum time commitment, and the monthly fee covers all parts, repairs, replacements, and costs / materials for shipping the grounds back. You don’t have to ship the grinds back, but you still pay monthly either way. 

While the bin will reduce the amount of trash that leaves your house, there are cheaper solutions for managing your food waste responsibly, including proper meal planning, non-electric countertop compost bins (if you’ve nowhere to put your scraps, there are organizations that can use them), and municipal and private composting programs. But Mill’s selling point is ease of use, and it’s a lot easier and less smelly than any of the above. 

Dropping food scraps into the pedal-operated Mill is as easy as throwing them in the trash, but unlike a regular trash can or countertop composting, the Mill isn’t messy, doesn’t smell bad (even with shrimp shells in there for three days), and never attracts flies.

For me, the main benefit was that I only had to empty it about once a month (an easy process), and because I was inputting less in my regular trash bin, that went out less often, too. Mill reports one customer who shipped a 25-pound box of food grounds back to them kept “8.5 standard trash bags out of the landfill.”

But, unless you can offset its cost by paying for a smaller garbage can from your municipality, Mill is a solution for rich people who care about the planet. Those of us who care about the planet but aren’t able to spend $33 a month for a more convenient way to do good and can’t recoup any costs from downsizing our garbage can are just going to have to keep sticking our food scraps in the freezer and lobbying the local council for better community composting. 

We shouldn’t waste food, yet we do. My family of four wastes an unconscionable amount due to busy schedules, picky eaters, and a too-big refrigerator that hides leftovers until they walk out on their own. 

We have chickens and a bunny rabbit, so fresh scraps from chopping veggies and fruits mostly find a happy home. But there is a very long list of things chickens can’t eat, including avocados, potatoes, onions, coffee grinds, and anything in butter, oil, or salt (so, most of what I cook). 

However, the Mill can eat all these things, which made me skeptical about how Mill Industries will turn these food grounds into healthy chicken food for local farms. According to Mill, the grounds go through several processing steps to make them safe for chickens. “We’re able to test it and blend it to get the right nutritious ingredients,” says Rogers.

But it turns out this is a thing they haven’t actually done yet, at least outside of the research stages. I wanted to try out their chicken food on my chickens, and while Rogers told me I could feed them the grounds directly, the company is still “working to make them into a safe chicken feed ingredient.” 

To create food for any creature, you need approval from the Food and Drug Administration and the version for animals, the Association of American Feed Control Officials (AAFCO). As no one has ever made commercial chicken food from household leftovers before (it has been done with restaurant and grocery store scraps), Mill needs approval for its process. 

While it’s not there yet, the company is getting close. This week, AAFCO approved a new definition for animal feed ingredients made from Dried, Recovered Household Food. There are still more regulatory hoops to jump through, but Mill spokesperson Molly Spaeth tells me, “We expect the two additional procedural votes to be completed by January 2024 at the latest. We have started [chicken feed] production now and are distributing in an R&D capacity until we have that full clearance in January.” 

I’m not intimately familiar with regulatory processes for animal food, but right now, Mill’s product doesn’t deliver on its core promise of turning your food waste into commercial chicken food. Until that’s a proven solution — i.e., the hens are happy — it’s basically a glorified trash compactor that you pay monthly for the privilege of using.

Hungry chickens aside, as a smart trash can, the Mill works well. It made disposing of my food waste easier than my nascent attempts at composting (which is not as simple as it sounds), and I felt less guilt dumping leftovers from my plate or chopping board in there than throwing them in the bin destined for the landfill.

The list of foods the bin can’t take is significantly smaller than things my chickens can’t eat — you shouldn’t put in large bones, hard shells, corn husks, rotten food, or copious amounts of sugar like a whole cake (who throws away a whole cake?!). There’s a handy list of dos and don’ts that attaches magnetically to the bin.

Unlike most of the tech in my smart home, the Mill required minimal attention. Open it with the foot pedal, discarded food goes in, the lid locks at 10PM each night, and the lengthy grinding begins (you can adjust the start time in the accompanying app). Setup was as easy as unboxing, popping in the bucket and large charcoal filter, and plugging it in — although I needed help as the whole contraption weighs a whopping 50 pounds.