Composting Fertilizers Gardening

Trying a Tero Food Waste Recycler

Tero food waste recycler on a counter

By Larry Hodgson

This summer, I had the opportunity to try the new Tero food waste recycler, produced by the firm Tero (teroinovation.com). I had recently been considering this type of food recycler to help take charge of my food waste during the winter months when I have no access to my composter, so the experience came at a very opportune time.

The Story Behind Tero

You may never have heard of the Tero food waste recycler, but it has been hugely newsworthy in Quebec, where it was developed. It’s hard to find a single news outlet, from television to radio to magazines and newspapers—and who knows how many web sites!—that didn’t cover the product, probably because the story behind it was just so uplifting. 

The designers of Tero: Valérie Laliberté and Elizabeth Coulombe.
The designers of the Tero food waste recycler: Valérie Laliberté and Elizabeth Coulombe.

It all began with two young women, Valérie Laliberté and Elizabeth Coulombe, students who undertook a study project in 2017 as part of their bachelor’s degree in product design at Laval University. They came up with a revolutionary design in waste reduction, a simple household device beneficial to the environment because it considerably reduces the waste products being thrown into the municipal trash. 

In October 2019, they launched a Kickstarter crowdfunding campaign which allowed people to pre-order their device. It was hugely successful, raising more than $1,750,000. Two years later, Tero devices are being delivered to the initial investors and the product is now available on the market.

How a Tero Food Waster Recycler Works

Even though several media have presented the Tero as a kind of composter, some even calling it a “countertop composter” for example, in fact, it doesn’t actually produce compost.

Rather than composting, in which kitchen food waste is allowed to decompose (break down) on its own, a lengthy process that involves allowing fungi, bacteria and all manner of mostly microscopic creatures to digest it, the Tero recycler takes food waste, heats it and grinds it up, reducing its volume by 90% and resulting in a ready-to-use dry fertilizer.

Finger on the Tero’s ignition button.
The Tero recycler produces usable and environmentally friendly fertilizer in just a few hours.

And, unlike composting, you don’t have to wait months for results. When you start the machine, the fertilizer is ready to use in just a few hours!

My Experience

I was interested in trialling a Tero food waste recycler with the idea of writing about it and after a bit of negotiation, the company agreed lend me a demonstrator I could use in my own kitchen if I wrote about my results. Well, duh, of course I was going to write about my experience! That’s what I do, write about things related to gardening. So, I received a Tero device for testing in July 2021. 

I knew beforehand that the Tero recycler was about the size of a bread maker, but still, I was still a bit taken aback by how large it was. Although designed to fit on a kitchen counter, at just under a foot tall (28 cm), it couldn’t fit on ours, as our cabinets are lower than average. If I’d placed it under the cabinets, it would have been impossible to open the lid! That wasn’t a major issue, though: we had a small cabinet on the floor right next to the main counter that suited it quite nicely. And the average user shouldn’t have this problem, as most kitchen cabinets are set at least 18 inches (45 cm) above the counter, leaving plenty of room for a food waste recycler.

Assembly was easy: just take the Tero out of its box and follow the illustrations in the accompanying printed User’s Guide (most importantly, you have to fill the filter with activated charcoal, included). In 3 or 4 minutes, the device was plugged in and ready to use.

Tero in a white kitchen.
The Tero recycler offers a sophisticated appearance well suited to a modern kitchen.

Its appearance is simple and sleek, very sophisticated: a rectangular box with rounded corners with a ventilation plate above and a start button and indicators on the front. There is even a choice of colors: white or black. Inside is a non-stick bucket that with a handle for easy removal so you can readily harvest your fertilizer and also for cleaning purposes. There are also two pairs of sharp blades inside the bucket, also easy to remove and clean.

Two printed guides accompany the Tero: a User’s Guide and a Fertilizer Guide. It was especially the User’s Guide that we first studied, because as we wanted to know what we could put into the bucket. Obviously, food waste, but which types of food waste?

I quickly learned that you can add almost anything you would put in a backyard composter, but also certain products that are usually banned from home composting, such as meats and certain bones.

Here is a summary of the possibilities:

Foods That Can Always Be Processed:

Knife pushing food waste into the Tero tank.
Most food waste will find a place in the Tero recycler.
  • Leftover fruits and vegetables;
  • Eggs and eggshells;
  • Leftover meats, fish and poultry;
  • Small bones of poultry and fish;
  • Cereals, grains, nuts (without husks) and legumes;
  • Coffee grounds and used tea leaves;
  • Cheese and solid dairy products.

Foods That Can Be Processed in Small Quantities:

  • Very sweet cakes and desserts;
  • Very salty foods;
  • Rice, pasta and starchy foods;
  • Very sweet fruits (pineapple, banana, melon, grapes);
  • Jams and peanut butter;
  • High fat food (dressing, meat fat, etc.).

These products are often too runny or become sticky and can adhere to the walls of the bucket or blades and make cleaning difficult, so are best added in small quantities mixed in with other wastes. Either that or they contain enough salt to potentially interfere with plant growth when the fertilizer is applied and you wouldn’t want that!

Foods That Can Never Be Processed:

  • Chewing gum and candy;
  • Cooking oils and other fats;
  • Any liquid;
  • Hard bones (beef, pork);
  • Hard shells (walnuts, pistachios, oysters, coconut);
  • Hard pits (mangoes, peaches, etc.).

And of course, avoid all waste that is not food (metal, fabrics, plastic, etc.), including compostable bioplastics.

In addition, the guide recommends varying the products you add to ensure a better quality of fertilizer (just like in an outdoor composter) and cutting some fibrous foods into small pieces.

Once we finished reading the guide, we started adding kitchen waste to the bucket. 

I was surprised to see that, in the end, we didn’t produce all that much waste. Although the guide recommends starting a cycle after five days to avoid the risk of odors, our bucket was barely half full after that time. It turns out that our device only gets close to its full capacity (there’s a line inside indicating how much material you can add) after about 7 days, not 5, so that became our normal time for launching a new cycle. Even after 7 days, we never noticed any unpleasant odor near the appliance, not even with the lid open and our nose almost in the bucket. 

Couple cutting fruit next to a Tero food waste recycler.
Your personal eating habits will determine what goes into the Tero device.

Obviously, what ends up in the tub reflects the habits of the family that runs it. We usually don’t peel our potatoes, carrots, apples, etc., and so this type of waste was missing and might explain our slowness in filling the bucket. On the other hand, we eat a lot of fruit, so apple cores, grape stems and citrus peels abounded. 

There was little risk that we put too many “very sweet fruits” in the bucket (one of the products only to be added at small quantities), because we’re just not in the habit of throwing fruits away. Even when we find a fruit is that bruised or otherwise damaged, we just cut out the damaged part and eat the rest. Only the damaged part, a very limited amount, will go into the recycler, so is unlikely to gum anything up.

Of course, over the weeks, there were plenty of exceptions. For example, my son, a heavy coffee drinker, once spent a week at our place. My wife and I drink little coffee, but that week, the bucket quickly filled up with coffee grounds! (And no, you can’t smell the coffee grounds, either!)

Painless Processing 

We had originally decided to try to start a processing cycle at bedtime so as not to be bothered by any noise, since, depending on the type of food being processed, processing can take 2 1/2 to 8 hours to complete (90 minutes of heating, several sessions of grinding depending on the inputs [the device does the math] and 30 to 60 minutes of cooling).

At least that was our intention. But in the end, we soon dropped the “overnight only restriction,” because finally the noise the device makes really wasn’t all that bothersome. The recycler is certainly quieter than our bread maker and much, much quieter than our vacuum sealer. 

In the adjoining living room with the television on, the sound is noticeable, but only barely. It’s more audible when we’re sitting in the dining room literally next to the device (I can almost touch it from my chair!), but not enough to disturb the conversion or force us to speak louder. The noise, which reminds me of tiny feet walking on gravel, quickly became “normal” and is now part of our routine.

The Results

Photo showing food waste before and after drying and shredding.
Food waste quickly becomes a fertilizer of variable particle size.

I have to admit that I was a bit surprised when I saw the fertilizer for the first time. I don’t know why, but I expected a uniform product: little granules of identical size, like a commercial fertilizer. But that’s not what you get! The result is a mix of dry materials with textures ranging from dustlike to up about 1 inch (2 or 3 cm) in diameter.

After our first cycle, for example, there were fairly large pieces of orange peel, somewhat rolled up and completely dry, but still easily identifiable by their orange color, and also pieces of onion skin, smaller than what we had put into the device originally, but still easily recognizable. 

Reading the Buyer’s Guide again, we realized that we had not followed the guidelines. It suggested cutting those two products (and also some fibrous vegetables, such as celery and asparagus) into small pieces before putting them in the bucket. Mea culpa! Now we cut up citrus and onion peels before adding them to the bucket and they no longer stand out.

Tero fertilizer in a hand.
Tero gives a fertilizer of variable texture … and that’s perfectly acceptable.

Despite this, each cycle contains a mixture of both fine and bulkier waste. And there’s nothing wrong with that. The biggest pieces offer the same beneficial properties as the smaller ones and will decompose and disappear when they’re in contact with moist soil. Thus, they can be used in the garden without any problem.

Even the enlarged tip of small chicken bones, the only part of the bone that doesn’t completely disappear, are perfectly sterilized and ready to continue decomposing in the garden. Still, I have to admit seeing bone residue creeps me out a bit (I’m not used to seeing animal parts in my fertilizer, however small!) and I remain hesitant about adding chicken bones to the recycler except for the very smallest ones. 

A Few Pleasant Surprises

And then there were a few positive results I wasn’t expecting.

The most striking was what happens to eggshells. 

When we compost conventionally in our home compost bin, eggshells never seem to break down, even if we grind the shells to tiny pieces before we add them. After all, they can still be detected a decade later as small white dots in the soil of our vegetable garden. After 50 years of composting, I am so used to the inability of eggshells to fully break down that it seems quite normal to me. But in the Tero device, an eggshell disappears completely. I mean, there one minute, gone the next! I find this so striking that I purposely leave the shell as intact as possible when I put it in the device just so that I can see afterwards that it’s completely gone. It’s like magic!

Also, there was the question of meat. We rarely throw away meat (usually we eat it!), so this is a waste product we really didn’t test much other than for a little gristle (if that’s considered meat). But one time there was a piece of meat we had to dispose of. I must admit we were a little hesitant about adding it to the recycler. Surely there would be a bad smell? But even though it was in the bucket for 4 days, therefore necessarily at room temperature, before we launched the next cycle, there was no unpleasant odor during the period of waste accumulation. Literally none: you never would have guessed there was meat on just the other side of the lid. And at the end of the cycle, it was completely gone. A total success!

I suppose over time we’ll make all sorts of other positive discoveries about the recycler. I must admit I always look forward to opening the recycle after a cycle, then literally run my fingers through the resulting fertilizer, checking out the results. Fascinating!

Using Tero Fertilizer

Tero fertilizer in a trowel ready to add to a garden.
The fertilizer produced by Tero is an all-purpose one that can be used on any plant.

The fertilizer produced can be used like any other fertilizer. You apply it to places where a mineral supplement will be useful: a vegetable garden, a flower bed, even the lawn! Like compost, it will be rich in nitrogen, phosphorus and potassium as well as several minor elements. The exact proportions of the nutrients will vary depending on what you originally put into the Tero recycler. 

In the garden, you can mix the fertilizer into the soil or you could skip that step, just applying it over the surface of the soil and letting the rain wash it in. The Fertilizer Guide that comes with the Tero machine gives some good ideas on using the fertilizer produced as well as recommendations for appropriate application ratios.

Tero fertilizer can also be used in patio containers, balcony gardens and houseplant pots, mixing it into the soil. In such a visible circumstance, you’ll probably want to make sure the fertilizer is completely covered with soil. If you leave it on the surface, you may see fungi forming. As gardeners, we know that these fungi are beneficial ones, further breaking down fertilizer particles so plant roots can absorb their minerals, but even so, visible fungi in a plant pot is not something just anybody is ready to accept! So, bury the fertilizer: out of sight, out of mind!

Note that the fertilizer produced can be stored for months (even years!) in a sealed container. So, during the winter months, when your plants have little need for minerals, but when you, as a human, continue to eat and produce food waste, you can store up fertilizer in preparation for the summer to come. In fact, why not prepare bags or pots of “homemade fertilizer” and give them as a gift to your gardening friends?

Composting or Waste Recycling: Which Is Better?

For people who have outdoor gardens, I see the Tero food waste recycler not as a replacement for composting, but as a supplement to it. Continue to compost your yard waste throughout the summer, as usual, but in the winter, when composting outdoors is more complicated, you can continue to recycle the food waste you produce with the Tero recycler.

The Tero device is going to be especially interesting for gardeners who don’t have access to a composter. Maybe they live in an apartment or condo, but wish they could do their part for the environment by recycling food waste. With a Tero recycler, you can now do so easily and thus feed your balcony garden!

Getting Your Own Tero Food Waste Recycler

Thanks to the Tero food waste recycler, you can now produce your own natural nutrient-rich fertilizer. Giving a second life to your organic materials has never been easier: fill the device’s bucket with kitchen scraps, start it up, then fertilize your various green spaces.

The commercial production of the first Tero devices has officially begun and the first units have been delivered. Delivery will continue over the next few months in Canada and the United States. To learn more or to get your own, visit teroinnovation.com.

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

13 comments on “Trying a Tero Food Waste Recycler

  1. Way to go ladies! It looks like a great product if you have the $ and the counter space. Fascinating about the egg shells.

  2. Joyce, Hamil5in, Ontario

    Thanks for a terrific post. Wonder if this could be done in a much larger scale to deal with restaurant etc organic waste?

  3. I don’t understand why you say that in Winter, outdoor food composting is “no longer logically possible.” Here in central New Jersey, and before in Eastern Pennsylvania, we’ve been composting through the Winter with no problems. Perhaps you should try it and report to us what you find in your locality. We find that intermittent freezing and thawing has little effect on the operation of our compost bins.

    Why also do you say that meats are not acceptable for natural backyard composting? I’m sure you know that you should cover any food waste adequately – ideally with a thin layer of topsoil – to avoid any problems, and when you do that no food waste presents problems, except for large animal bones, clam shells, and a few other things that take very long to break down.

    I’m not in favor of the Tera, mainly because it must consume too much electricity in order to grind and dry the food. You didn’t tell us the power consumption. I suggest you plug it in your wall outlet using a “Kill A Watt” energy logger and tell us what you find. Interesting that I cannot find out the electric consumption on the Tera site or on the www. This arouses suspicion in me.

    • The energy consumption of the device is estimated at 65kWh per year for 2 cycles per week. This represents a similar consumption as an electric coffee maker started every day.

  4. I’m sort of railing against this. Unless you have solar power then it’s a very high carbon way of dealing with your waste, it is probably better that it goes in green bin collections if they have them or if you have a garage a workers or for those of us with gardens it goes on the compost heap which will deactivate once it warms up. If snow is as issue build your compost heap a shelter.

  5. I see this as a great device, for apartments & yard less home. It is a great way to compost with out the mess of worms & compost piles. It is not for people who have chickens & pigs, large garden lots.

    • Even as I tested the device, I was still composting outdoors. It couldn’t have handled the much larger quantity of plant residues an outdoor garden produces. It’s really for small scale fertilizer production.

  6. 1) I assume the heating process drives off the water to dry it?
    2) Do you know how hot it gets? The web site claims it kills pathogens so that would need to be quite hot.
    3) I can’t imagine there is much decomposition taking place in a couple of hours – I wonder if it is really decomposed enough to release the nutrients?

    • Hi Robert. I’ve just been having fun test driving the apparatus, so don’t have all the details. Tero has quite a bit of information on their web site about the end product and its fertilizing capabilities. And if you don’t find answers to all your questions, contact them and I’m sure they’ll get back to you.

  7. Thanks for this informative review -I am exploring options ,have limited knowledge and found this very helpful .

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