Frequently asked questions

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Because we have a limited supply of bins, we’re starting with a reservation system. We’ll be releasing new batches of bins every month, starting spring 2023. If you’d like to be one of the first people in line for a Mill Membership (and a bin), you can reserve now with a fully refundable $33 deposit.

At Mill, we’re doing things a little bit differently. The bin is only part of a Mill Membership and can’t be purchased separately.

It’s a membership because the management of wasted food is bigger than any single device. The average household will generate 150-200lbs of Food Grounds per year, and Mill helps our members manage that volume, and put it to good use.  It's not just a better kitchen experience; it's also a fully closed loop.

Your membership also includes:

1. Impact tracking and app 2. Charcoal odor filter replacements 3. Dedicated member support 4. Membership warranty 5. The option to send Food Grounds via pre-paid shipping (once a month for most members)

The Mill kitchen bin turns kitchen scraps into dried, ground-up food that we call Food Grounds. Food Grounds are still food, minus the water, bulk, odor, and ick.

Food Grounds aren’t compost. Compost is produced when microbes digest kitchen scraps, which takes weeks or months, not hours — despite what others might say. While Food Grounds can be made into compost or added to your garden, it is a delicate process that can result in mold, cause odors, and attract pests.

Sending us your Food Grounds is not required, but we highly recommend it because it is the most practical way to keep your kitchen scraps in the food system, as we work to turn them into food for chickens.

The food we throw away is still food. It takes a lot of land, water, fertilizer, and effort to get food from the farm to our tables — so it’s important for our food to stay in the food system. There are ways to make the best use of food that’s uneaten. First, feed people. Then, feed animals that produce food for people. Both options align with the EPA’s food recovery hierarchy and the hierarchy of destinations for achieving United Nations Sustainable Development Goal Target 12.3.

We’ll take the Food Grounds you send us, homogenize them, and work to turn them into food for chickens.

Currently, we’re working through the necessary scientific and regulatory processes to establish a safe and nutritious chicken feed ingredient we can distribute commercially. We’ll share more on our progress later this year.

We designed the Mill kitchen bin to dry, shrink, and de-stink kitchen scraps as efficiently as possible via long, low-energy cycles. Your energy use will depend on the amount and kind of kitchen scraps you add to it. We estimate the bin will use around 1 kilowatt-hour (kWh) of electricity per day, averaged over multiple weeks of usage (if you generate around 1.5lbs of kitchen scraps per day). Today, that’s about the same amount of energy per day as an energy-efficient dishwasher, but with software updates, the bin will keep getting better and more efficient over time.

The cost of energy will depend on your local energy rates — you can check your energy bill to see how much you pay per kilowatt-hour (kWh). At $0.20 per kWh (approximately the national average), that’s about $6 per month.

Want to use less energy? Try limiting liquids by doing things like straining wet foods before adding the solids to the bucket.

Big picture: based on our preliminary study, you can avoid about a half-ton of greenhouse gas emissions per year with a Mill Membership. Instead of filling the air with methane, your kitchen scraps can go back into the food system, as we work to turn them into food for chickens. To learn more about the climate impact of an annual Mill Membership, click here.

Yes. If you decide to cancel your reservation (before your membership starts), your deposit will be refunded to the original form of payment. Go to your Member portal to cancel your reservation. Otherwise, your deposit will go toward your first membership payment.

Your membership comes with prepaid boxes that you can empty your Food Grounds into. The average household will need to empty their bin every 2-3 weeks, but it really depends on the amount of kitchen scraps you generate. Each box holds about two bin-fulls, so most members will send a box roughly once a month. You’ll know it’s time to empty the bin when the Food Grounds get close to the fill line inside the bucket.

We designed the Mill Membership to be the most practical way to manage kitchen scraps.

– Shrunk and de-stunk: Your membership comes with a Mill kitchen bin that dries, shrinks, and de-stinks your kitchen scraps. No weird smells. No drippy bags. – Not-so-picky-eater: Unlike compost, the bin can handle whatever you can’t eat — even meat and dairy products. – Fewer trips to the bin: Add kitchen scraps to your bin all day, every day. The bucket can collect dry, compact Food Grounds for weeks without needing to be emptied. And you don’t need any additives. – Year-round service: You can ship your Food Grounds to Mill even in the winter when curbside compost collection services may not be available. – Impact tracking: See the amount of kitchen scraps you’re adding and learn ways to improve your climate impact over time.

We design and test every Mill kitchen bin to be durable and long-lasting. And because using a Mill kitchen bin requires a  Mill membership, all bins are eventually returned to us.

This membership model enables us to support every Mill kitchen bin through its lifecycle, from shipping and first use to refurbishment and extended use.

We ensure that no bin is unaccounted for, abandoned, or wasted, and are developing programs for bins that are no longer used for active Mill Memberships, specifically education programs with non-profits. If you have any suggestions on organizations we should engage, please contact us.

Composting is a form of biological digestion that breaks down food and takes weeks or months, not hours or days. Be wary of any claims to the contrary.

The Mill kitchen bin isn’t a composting device. The Food Grounds that come out of the bin are still food, minus the water, bulk, odor, and ick. The bin is designed to conserve all the potential in your kitchen scraps, not break them down, so we can keep them in the food system.

On top of that, we designed the Mill kitchen bin to be so much more practical and convenient than any other way of managing kitchen scraps.

– Large capacity: add kitchen scraps to your bin all day, every day. The bucket can collect dry, compact Food Grounds for weeks without having to be emptied. – Automatic cycle: the bin runs at a set time every day, zero effort required. – Odor filtering: the filter is packed with 5 lbs of charcoal and lasts six months for most households. We automatically send replacements (included in your membership at no extra cost) before you start noticing any smells. – App: see what’s happening inside your bin, create a custom schedule, and get alerts when there’s something you need to pay attention to. Otherwise, your bin will do its thing. – Impact tracking: see the amount of kitchen scraps you’re adding and learn ways to improve your climate impact over time.

You put in kitchen scraps and the Mill kitchen bin will automatically dry and grind them overnight (or whenever you schedule your cycle to run).

- The Dry & Grind cycle slowly heats and mixes your kitchen scraps in order to conserve your food’s nutrients.

- Each cycle varies depending on the amount and moisture content of kitchen scraps you put in. Wet kitchen scraps like fruit will take a little longer, and dry scraps like bread will be shorter.

- The bin can take a while to grind up food because it runs a low power, energy-efficient cycle.

- If you add less than 1.5lbs of food, the cycle will typically take less than 6hrs. Each additional pound of food you add will increase the length of the cycle by roughly 1.5hrs. So if you have a really heavy day, don’t be alarmed if your device runs up to 18 hours.

- It's fine to keep adding food while your bin is running. The cycle will adjust to dry longer depending on how much & when you put more in.

When the Mill kitchen bin is running a Dry & Grind cycle, the fans sound like white noise and are about as loud as a dishwasher (~44 dB). If you put in pits or bones, you might hear a quick, loud snap. Every now and then it might make a funny creak or groan as it mixes.

As a general rule of thumb, if it comes off your cutting board, you can add it to the Mill kitchen bin.

Here are some examples:

– Small bones (like chicken or fish) – Fruits – Vegetables – Rinds, peels, pits – Meat, dairy, eggs – Plate scrapings

Things that don’t belong in the bin:

– Large bones (like beef, lamb or pork) – Hard shells – Large amounts of liquid, grease, or oil – Large amounts of sugar, cake, or cookies – Houseplants or flowers – Drugs or medicine – Compostable plastics, packaging – Take-out containers, paper plates

Charcoal filters are a critical component of the Mill kitchen bin’s odor management system. We selected a coconut-based charcoal among other varieties for its long-lasting ability to reduce odors and natural material profile.

The life span of the filter is typically six months and can vary based on how often you add kitchen scraps to your bin and how smelly they are.

We automatically send replacements (included in your membership at no extra cost) before you start noticing any smells.

After replacing the filter, ship back your old filter to us. We prioritized the use of a refillable canister to minimize plastic waste and to have the opportunity to recycle the charcoal material.

Uneaten food is the most common material in landfills and most of it comes from our homes. When that food rots, it produces methane, a greenhouse gas that is 80x more potent than carbon dioxide over a 20-year period.

Based on our preliminary study, you can avoid about a half ton of greenhouse gas emissions per year with a Mill Membership. Instead of filling the air with methane, your kitchen scraps can go back into the food system, as we work to turn them into food for chickens.

To learn more about the climate impact of an annual Mill Membership, click here.

Mill members have the option to send their Food Grounds to us whenever their bin gets full, in order to keep their kitchen scraps in the food system and out of the landfill. Prepaid return boxes, shipping fees, and scheduled pickups are all included in the Mill Membership.

Based on our preliminary study, you can avoid about a half-ton of greenhouse gas emissions per year with a Mill Membership. Instead of filling the air with methane, your kitchen scraps can go back into the food system, as we work to turn them into food for chickens.

We are partnering with USPS to ship Food Grounds because they’re already visiting almost every house, every day. And since Mill households will, on average, send just one box of Food Grounds every few weeks, USPS vehicles will have the capacity to manage the load.

With this approach, every box of Food Grounds could be transported 15,000-20,000 miles (close to a trip around the world) before it could negate the benefits of keeping food out of landfills and avoiding methane emissions.

For the Food Grounds packaging, we use a recyclable LDPE plastic slide-lock liner in a 100% recyclable cardboard box. Since we receive every box of Food Grounds at our feed facility, we’re able to inspect and sort the boxes for reusability and recycle the bags.

We’re also actively exploring other sustainable packaging options. If you have any suggestions, please contact us.

To learn more about the climate impact of an annual Mill Membership, please click here.

The Mill kitchen bin is manufactured at a LEED-certified facility in Guadalajara, Mexico. We prioritized manufacturing in North America to minimize the greenhouse gas emissions impact of shipping bins from the factory to the homes of our Mill members.

Our manufacturer also requires their supply chain to commit to their Responsible Business Alliance Code of Conduct to ensure the health and safety of the employees at the facility.

At this time, we’re identifying our initial partners who are interested in purchasing a chicken feed ingredient produced from recovered household food. We’ll be deliberate and thoughtful about our selection of potential farm partners, taking into account concerns about the environmental, welfare, and equity impacts of various production models.

We’ll share more about our progress later this year. If you have any suggestions, please contact us.

For the kitchen bin packaging, we use 100% recyclable cardboard for the box and foam for the interior. We hate the foam deeply, but it was the best available option to ensure the bin arrives undamaged from our factory to your door. We vetted mushroom packaging, molded fiber, and a bunch of other sustainable options — none of them could protect a device of our size. We’re nevertheless committed to continuous improvement and are engaging with new providers who offer curbside recyclable foam alternatives.

For the Food Grounds packaging, we use a recyclable LDPE plastic slide-lock liner in a 100% recyclable cardboard box. This solution offers Mill members the most practical way to keep their Food Grounds out of landfills. You can read more about the climate impact here. Since we receive every box of Food Grounds at our feed facility, we’re able to inspect and sort the boxes for reusability and recycle the bags.

We’re also actively exploring other sustainable packaging options. If you have any suggestions, please send them to us at mill.com/contact.

We consider conservation in every decision we make — from sourcing product materials to community outreach.

We’re internally tracking what we’re doing, what we consider, and how we’ll get better across each area of our business.

– Device production: building and delivering Mill kitchen bins for households. – Household participation: improving household kitchen experiences. – Membership services: improving Mill member experiences. – Maintaining food pathways: enabling highest and best end uses for Food Grounds. – Overall: building Mill as a sustainable company.

We’re building an approach that covers: – What we do to stop waste. – How we prevent emissions. – How we help people.

This approach is embedded into our company onboarding program, our product development process, and our company-wide goals. We’re looking forward to sharing more about our progress. If you have any suggestions, please contact us.

We use a life-cycle assessment (LCA) to quantify the impact of an annual Mill Membership.

Prior to having data from households with Mill Memberships, we prepared an externally reviewed Scoping LCA as an interim modeling effort. This is typically used to identify “hot spots” — areas of a process or business which are disproportionately impactful.

By publishing our initial estimates, we want to invite more people to help shape how we think and how we outsmart waste. To learn more about the climate impact of an annual Mill Membership, please click here.

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