Mill Bin Review: Turn Gross Food Scraps to Dirt in 6 Hours – Just Don’t Call It Compost – CNET

And it’s definitely not a composter.   

The Mill bin doesn’t make compost — and that’s OK

Mill doesn’t claim that its bin makes compost like its competitors — the Lomi, Vitamix FoodCycler and Reencle Prime among them — and that’s by design. Mill argues those other machines can’t make real compost that quickly anyhow. 

“It is scientifically impossible to make compost overnight,” Mill President Harry Tannenbaum told CNET in an email, “which is why we are very careful not to call the Mill kitchen bin a composter or what it makes ‘compost.’ Any company or product claiming to make compost overnight is greenwashing, and taking advantage of people who want to do the right thing.”

Instead, Mill’s approach involves a closed-loop subscription service where apple cores, avocado pits and moldy bread are ground and dried inside a leased smart bin and sent back to be sold as an ingredient for making chicken feed. 

The Mill subscription costs $33 a month, or $396 per year, a recurring fee that includes free pickup of processed scraps and the use of the smart kitchen bin (with the subscription you don’t own the bin). The subscription also gets you free filter replacements (needed about every 60 days) and servicing, should anything go wrong. That cost is about the same as the price of a curbside composting program, and most of those don’t include a smart bin.

Mill just launched a nonsubscription model too, but it’s a budget-buster. The machine costs a whopping $899 to buy outright and includes a year of filters but doesn’t include material pickup. 

How the Mill setup works: What you can and can’t process

Setting up the bin and a profile in the app took only a few minutes. The most laborious part was moving the bin around the kitchen, since it weighs 50 pounds.

The Mill bin starts grinding and dehydrating food at whatever time you tell it to via the mobile app. It takes about six hours to complete a cycle, so right before bed made the most sense for me. After a few audible and dog-startling grunts, the Mill eases into action and emits only a soft whirr for the remainder of the cycle. 

In the morning, like magic, gnarly food scraps have been transformed into something that looks a lot like rich soil or compost. I disposed of shellfish, salmon skin, moldy bread and other classically smelly things in my Mill and never once awoke to an unpleasant odor. 

The handy app tells you when it’s time to empty the contents of the Mill into a prepaid shipping box and schedule a pickup. It’s not hard to judge this on your own, though, in case you don’t want another mobile app telling you what to do.

To test the processed food’s viability, I mixed some with planting soil, roughly half and half, and tried to rehouse an aloe plant. It died within a few days. As a reminder, Mill doesn’t claim the output is fit for nourishing plants. I was just hopeful, I guess.

On that subject, I spoke with someone about what can be done with Mill material if you choose not to send it back. Sally Brown is a research professor at the School of Environmental and Forest Sciences at the University of Washington and a self-proclaimed soil nerd. She told me that though dirt alone can’t support plants, it can be mixed with mature soil in your yard or garden, where it’ll continue to compost on its own and eventually deliver nutrients to the surrounding flora. Using a ratio of 1-to-10 (Mill dirt to soil) is recommended.

While Mill is very clear about its machine not making viable compost, it does give your food scraps a huge headstart if you plan to treat them and turn them into real compost on your own.

Mill material can also be safely scattered or diffused in most outdoor areas. Just don’t expect a bounty of wildflowers to spring up. 

The Mill system is great… if you can afford it

The cheapest fix for food waste is classic at-home composting, but it’s tricky to do and takes dedication and commitment. It’s also an odorous affair, particularly if you live in tight quarters or up several flights of stairs and can’t get the food waste outside immediately. Freezing food scraps until you can transport them to an outdoor pile helps. Here’s our guide to starting a compost pile and our step-by-step explainer on how to build a (surprisingly not gross) worm farm for composting. 

Other curbside compost services

Other private compost pickup services exist, but most don’t include a smart bin. They’ll retrieve your kitchen waste every week to be reused or recycled in other ways. They typically cost anywhere from $25 to $40 a month, depending on where you live.

Cheaper smart kitchen bins and countertop composters 

All three of Mill’s competitors offer countertop models that are hundreds of dollars cheaper. The Lomi by Pela, which we tested in 2022, is $500 for the machine but can be had for as little as $300 on sale. Vitamix’s FoodCycler, one that we’re currently testing, starts at $400 for the base FC-50 model. The Lomi and FoodCycler also have recurring costs in the form of pads and filters. For Lomi, they’ll run you about $9 per month.  

Reencle, which makes the boldest claims about turning food scraps into nutrient-rich fertilizer in two days using microbes that emulate the human digestive system, sells a composter that starts at $500. Dr. Brown, who works with Mill, told me you can’t really make true compost that quickly. We’re planning to test this model to see if it can. 

Food waste is too big a problem for one appliance. But every little bit helps