The countertop kitchen composter is a lovely thought. Instead of a smelly bucket of vegetable scraps and coffee grounds breeding fruit flies on your counter or attracting rats to your backyard, you could just put it all into a nifty electric gadget, and at some undetermined point in the future you’ll have a bountiful supply of nutrient-rich compost to use in your garden.
Unfortunately, none of the more popular electric kitchen composters do exactly this. Even though some of these devices are marketed as “composters” and have instruction booklets and apps detailing all the ways in which one can use compost, the vast majority of kitchen composters are just going to grind up and dry your food scraps. You will greatly reduce your waste output, and it will no longer smell, but if you’re hoping to put eggshells and banana peels into a machine and magically scoop out the kind of compost you’d buy at the garden center, that’s just not going to happen.
That said, you can mix small amounts of these grounds into potting soil in tiny ratios or use them as a feeder for a “real” compost pile. But again, most of these machines are meant for reducing the volume of household food waste. This is, itself, a legitimate goal, as cast-off food makes up 24 percent of municipal solid waste, resulting in the release of methane, a destructive greenhouse gas, as it breaks down in the landfill.
Or maybe you’d just like your food grounds to be odor-free and shelf-stable before adding them to your green waste bin for municipal composting or your backyard compost. In any case, despite critics’ cries of greenwashing and corporate astroturfing, there is indeed value to these devices. They make people more aware of their food waste. They don’t use a huge amount of power (around 1 kilowatt-hour was typical in my testing). And my top pick, the Reencle Prime (8/10, WIRED Recommends), even produces something close to compost.
Also, be sure to check out our guides to the Best Indoor Gardening Systems, Best Gifts for Plant Lovers, and Best Smart Bird Feeders.
Updated July 2026: I’ve updated my review of the Reencle devices to address an issue with broken paddles, added long-term testing notes on the Reencle Gravity, included new information for the Mill and GEME Terra II, and ensured up-to-date links and prices throughout.
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As I mentioned above, none of these machines makes truly ready-to-use, biologically stable, fully decomposed compost, but Reencle comes the closest to creating what you’d scoop out of a traditional compost bin or pile. Popular in South Korea years before it appeared in the US, the Reencle arrives with a starter bag of Reencle Compost Starter 1.0 (which you can purchase separately for $65) containing activated carbon, wood pellets, glucose, and a trio of patented thermophilic microbes ready to chow down. There’s also a prefilled charcoal filter that slots into the back.
The Prime is too large for a kitchen counter, but it conveniently operates much like a heated trash can. The lid opens via a sensor at the bottom or a button on the control panel, and it goes into your organic matter. That’s it. There are no cycles, tablets, or auxiliary buckets to worry about. Even the app is totally optional. Within hours to days, depending on the item, the scraps break down into a material resembling a cross between dirt and sawdust.
The smell isn’t always pleasant, but you can usually mitigate this with the control panel’s Dry and Purify buttons or by adding what, in composting lexicon, is called “browns”—dry, carbon-rich materials, like bread or shredded paper.
Photograph: Kat Merck
The Reencle also tends not to stink when you feed it its preferred diet of 1.5 pounds of scraps per day. Unlike other machines, it can also accept meat and dairy. For larger households, there’s the Reencle Gravity ($649), which is a couple of inches taller and can accept 3.3 pounds of waste a day. I also tested this and found it to be significantly quieter than the Prime—not that the Prime is noticeably loud, only about 30 decibels. The Gravity is nearly silent, which is a nice bonus. I did, however, find that over time, the Gravity contents went anaerobic (read: smelly) much faster than with the Prime. The increased volume seemed to retain more moisture. If you go with a Gravity, I recommend keeping plenty of browns (old bread, shredded paper) on hand to maintain microbial balance or adding in an additional few sessions of manual stirring per day with the included shovel.
When the volume reaches the fill line on each model, it’s time to scoop out the grounds. At this point, you can mix the grounds with potting soil at a 1:4 ratio and leave it to cure for three weeks (I used a large tub in my garage). Afterward, you can use it for both outdoor and indoor plants. I’ve used the resultant mix to positive effect both indoors and outdoors.
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