Sign In or Create an Account.

By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy


Close the Freezer. The Future of Composting Is Dehydrated.

The surprisingly strong case for Mill.

A Mill composter.
Heatmap Illustration/Mill

Food waste is a climate disaster, responsible for twice as many greenhouse gases as the global aviation, shipping, and paper industries combined. The food system generates about a third of our emissions, and nearly a third of the food it produces never makes it to our stomachs, which means we waste nearly a third of the farmland, fuel, fertilizer, electricity, irrigation water, and deforestation that goes into producing our food. At the same time, the 40 million tons of uneaten food that Americans send to landfills every year can decompose into heat-trapping methane, which also isn’t great.

But maybe Harry can help.

Harry is a sleek white Wi-Fi-connected garbage bin in my family’s pantry, a “food dehydrator” that transforms our kitchen scraps into chicken feed. It was created by Mill, a San Francisco-area startup that has raised more than $100 million to try to keep more household waste inside the food system. Mill’s founders built the Nest thermostat that limits household energy waste, so they know something about using high-tech hardware to try to adjust consumer habits in climate-friendly ways. They’ve shipped thousands of bins since April, and they say they’ve got more demand than their Mexican factory can supply.

Every day, my family tosses banana peels, pizza crusts, eggshells, moldy salmon, wilted celery, and other leftovers into Harry. Every night, Harry spends about six hours heating, grinding and shrinking them into nutrient-rich feed that looks like a cross between coffee grounds and dirt. Food waste is about 80 percent water, and Harry dries it out; it takes almost two months before the bin gets full and I have to mail the grounds back to Mill.

It’s a seamless user experience, with no smell, no schlep, and so far, virtually no noise. The bin has a cool wood-veneer lid with a convenient foot pedal to lift it; Mill CEO Matt Rogers helped engineer the iPod and iPhone at Apple before he started Nest, so he knows something about good design, too. And the company has calculated that its bins will help the average household avoid about half a ton of emissions every year, not even including the deforestation that won’t be needed to grow the chicken feed Mill will replace.

Mill’s app prompts you to name your bin upon arrival, and we named ours after Mill president Harry Tannenbaum, an engaging climate wonk who charmed me with his frequent use of the word “putrescence.” (I initially wanted to name it Wastoid, but my wife informed me that was stupid.) Tannenbaum got the idea for Mill after learning that food waste is the largest component of U.S. landfills.

“That freaked me out,” Tannebaum said. “Not only are we disconnecting those nutrients from returning to the earth by entombing them in landfills, they’re creating methane that cooks the earth. And it’s all starting in our kitchens.”

Composting can keep food waste out of landfills, too, but only 4 percent of U.S. households compost, because separating and storing food scraps can be a time-consuming, odor-producing, rodent-attracting hassle. And unlike many composting programs, which have absurdly complex requirements about what can be used, Mill’s bins can recycle just about everything except big bones, liquids, and excessive sugar. But their real bonus for the planet is that while compost can be used to help grow food, Mill’s grounds are still basically food. This summer, the Food and Drug Administration and the Association of American Feed Control Officials cleared the way for their use as commercial poultry feed, a much higher use than compost on the EPA’s food recovery hierarchy. It’s the first step in getting those grounds into the hands of chicken farmers.

It’s nice that my family no longer has to take out our regular trash so often, now that we no longer dump food into it, and I get a kick out of leaving Harry like this at night:

The author's Mill, filled with food.

and seeing this the next morning:

The author's Mill, now filled with grounds.

It’s real bio-recycling, and while Mill would only be able to feed 7 percent of U.S. chickens if every U.S. household had a bin, every soybean that Mill can replace is a soybean that doesn’t need to be grown in the Amazon. And Harry helps us notice what we’re not eating — Instacart, you’re sending us too many mushy grapes — so that we can buy less of it and avoid waste on the front end.

That said, Mill is letting me use Harry for free, because I’m a dork who writes about food and climate change. I might be less enthusiastic if I were paying the hefty normal-human rate of $33 a month for the privilege of using its bins. Some composting services cost almost that much, and Mill emphasizes that its bins can take the stink and ick out of the kitchen experience — no putrescence! — but realistically, they provide more benefits for the climate than for consumers, which will limit the universe of consumers willing to shell out $396 a year for them.

Tannenbaum says Mill makes more economic sense in communities with “pay-as-you-throw” garbage collection, because Mill customers can save money by stepping down to smaller trash cans; in a pilot program in Tacoma, Washington, those savings have often reduced Mill’s effective cost to $8 a month. Mill is also working on deals with apartment buildings to provide bins to all their residents, so they could have easier trash management and less disgusting trash rooms. And corporations looking to shrink their carbon footprints could shrink their janitorial costs as well by putting Mill bins in their cafeterias. Tannenbaum points out that at Nest, after early-adopting consumers proved that smart thermostats could reduce energy waste, utilities helped defray the costs of moving Nest into the mainstream.

But change is hard, especially behavioral change. And change is slow, which is a problem, because the U.S. has set a goal of cutting food waste in half by 2030. There’s no way Mill can scale up fast enough to make a serious difference without government help. And that’s true for all kinds of food waste solutions — behavioral approaches like Britain’s “Love Food Not Waste” marketing campaign; policy reforms like tax breaks for restaurants that donate leftovers; and technologies like invisible biotech peels that prevent fruit and vegetables from spoiling. Our species is not going to wake up one day and make a collective decision to stop wasting a billion tons of food every year. We’ll need shoves (and cash) to overcome our inertia.

In fact, the U.S. Department of Agriculture announced last week that it’s investing $25 million in avoiding food waste. That’s a nice gesture, enough to fund 60,000 Mill bins for a year. But it’s a pittance compared to the $23 billion that USDA is spending on “climate-smart agriculture” — mostly regenerative farming experiments that, to put it charitably, will have an uncertain effect on emissions — and especially compared to the $428 billion in the last five-year farm bill.

Until recently, climate policy was seen as energy policy. But the world is starting to understand that unless it dramatically slashes emissions from the food system — at least a 75 percent reduction by 2050 — it won’t meet its climate goals even if it stops using fossil fuels. Congress is now talking about a new farm bill, and history suggests its main thrust will be to keep shoveling big money to big farmers. But it’s also an opportunity to make real investments in scaling up climate-friendly agricultural innovations like drought-tolerant super-trees, meat and dairy substitutes, alternative fertilizers, and food waste recycling options like Harry. Our energy and climate problems aren’t getting better fast enough, but our food and climate problems are still getting worse, and we’re not going to fix them by doing the same things we’ve always done.

That’s just putrescence.

Michael Grunwald profile image

Michael Grunwald

Michael Grunwald, a Miami resident, is the author of The Swamp: The Everglades, Florida, and the Politics of Paradise. His next book will be about food, land, and climate change.


Why Republicans Grilled the Energy Secretary About UFOs

You have to get creative when you allege a “war on energy” during an oil boom.

Jennifer Granholm and UFOs.
Heatmap Illustration/Getty Images

When Donald Trump met with a group of oil executives at Mar-a-Lago last month, his message was somewhere between “refreshingly blunt” and “blatant shakedown.” Attendees spilled to The Washington Post that Trump told the executives they should raise a billion dollars for his campaign so he could make them even richer by reducing their taxes and removing regulations on their industry.

One can’t help but wonder if any of them thought to themselves that as appealing as that kind of deal might be, there’s no reason for them to be desperate. After all, the Biden years have actually been quite good for the fossil fuel industry.

Keep reading...Show less

Biden’s Long Game on Climate

The president isn’t trying to cut emissions as fast possible. He’s doing something else.

President Biden playing chess.
Heatmap Illustration/Getty Images

Here’s the problem with President Joe Biden’s climate policy: From a certain point of view, it makes no sense.

Take his electricity policy. At the top level, Biden has committed to eliminating greenhouse-gas pollution from the power sector by 2035. He wants to accomplish this largely by making clean energy cheaper — that’s the goal of the Inflation Reduction Act, of course — and he has also changed federal rules so it’s slightly easier to build power lines and large-scale renewable projects. He has also added teeth to that goal in the form of new Environmental Protection Agency rules cracking down on coal and natural gas.

Keep reading...Show less

AM Briefing: Greenlight for Geoengineering?

On the return of geoengineering, climate lawsuits, and a cheaper EV.

Sunrise over a mountain.
Heatmap Illustration/Getty Images

Current conditions: Battered Midwest in for more bad weather this weekend • Tornadoes keep hitting the Great Plains • A heat wave in New Delhi that pushed temperatures above 116 degrees Fahrenheit on Friday is expected to last several more days.


1. Red states challenge climate lawsuits

Nineteen Republican-led states are asking the Supreme Court to stop Democrat-led states from trying to force oil and gas companies to pay for the impacts of climate change. Rhode Island in 2018 became the first state to sue major oil companies for climate damages and has since been joined by California, Connecticut, Minnesota, and New Jersey. The states pursuing legal action against oil companies are trying to “dictate the future of the American energy industry,” the Republican attorneys general argued in a motion filed this week, “not by influencing federal legislation or by petitioning federal agencies, but by imposing ruinous liability and coercive remedies on energy companies” through the court system.

Keep reading...Show less