The Zero Waste Coffee Project

Feeding Black Soldier Fly larvae with coffee pulp. An interview with Laura Stanford of THE BUG PICTURE, Kenya.

Note: This blog post is a little longer than it usually would be. But whenever I wanted to cut one or the other passage, I had the feeling that something essential, something important was missing. So the interview with Laura Stanford, which is already a very abridged version of the whole conversation that I had with her, is a little bit more "time demanding". But I think the extra length is worth it.

Laura, thanks for taking your time for this interview! You once mentioned that you dedicated your life to insects to make the world a better place for your children. Are insects, such as your favourite, the Black Soldier Fly, an alternative means to reducing our organic waste produced globally? Can they help to limit greenhouse gas emissions? Are they a good source of protein to meet increasing global demand, at least regarding animal feed? And to touch on our particular subject, how can they help farmers, especially coffee farmers?

They're definitely capable of doing all these things. They are remarkable insects as you well know, because you've been spending time researching them. I think that coffee pulp is a complicated substrate, but we'll put it this way: no single feed stock made from only one ingredient is ever going to be the solution as a diet for black soldier fly larvae, because the flies are like nearly any other creature on the planet in that they require a balanced diet. If you feed them exclusively with coffee pulp or banana peel, for instance, they will survive, but you're not going to get a great bug that is fat and beautiful and able to mate effectively. So it's about how do you balance that diet for the bugs while maximizing the amount of coffee pulp that you feed them.

I agree that there is such an opportunity here, because coffee especially has a bit of a bad name with reference to carbon emissions and all of those things, so it's a great opportunity to put a positive spin on the coffee story. The fact that you've got large washing stations means that you're collecting the stuff all in one place anyway, so there's a lot of reasons why this makes a lot of sense.

Are there any challenges with using coffee pulp as feed?

Yes, there are! One of the biggest challenges is that the coffee pulp is high in tannins which makes it a little bit tough for the bugs to digest, especially if the feed is overwhelmingly heavy on pulp. We settled in at our facility for an inclusion ratio of somewhere between 10 and 30% coffee pulp, and we found that the bugs could be really happy on that diet. We also leave the pulp for a few days, to allow the tannins to relax a bit, the food to decompose a bit to make it easier for the bugs to consume and receive the nutrients.

As I said before it is important to have a balanced diet. If the rest of the diet is incredibly rich in protein and carbohydrates and all of the things that the bugs need, then they're able to process that a lot easier. If you are dealing with what you might call “municipal waste'', then that's really hard for the bugs because they're not getting incredibly strong nutrients coming from the coffee pulp and they're not getting easily accessible nutrients from the municipal waste.

The biggest success with using coffee pulp comes if you're able to formulate a feedstock for the bugs that includes the pulp at as high a ratio as possible, but by also giving them other good organic waste, stuff like kitchen scraps from restaurants, because that's incredibly high in nutrients for the bugs. I'm actually not sure if you are allowed to use restaurant waste in western countries, but here in Kenya or Rwanda it's not a problem.

We were feeding the bugs in the beginning with green banana peels, which is not a great diet in combination with the coffee pulp, and as a result, they didn't love it so much. When we did more formulated feeds with things like abattoir waste, kitchen waste, or waste from a juicer, like beautiful mango peels, pineapple peels, those things, then the bugs performed incredibly well.

It´s all about balance.

Do you have to prepare these different ingredients, like grinding for instance?

We grind everything anyway because this increases the surface area allowing easier access for the bugs as well as more refined and rich frass which is the insect manure and a powerful organic fertilizer. The coffee pulp itself doesn't really need to be ground because it's already been pretty opened up.

One of the risks that we found was that if the feedstock was not completely favorable for the bugs and they were struggling to process the feed, it might start to spoil. It would get this, I want to call it a mold, but it's not really a mold, it looks like a white covering on the substrate, which then hardened and made it a little bit difficult for the bugs to move through the substrate which is important for continued access to nutrients.

If you don't grind and mix your waste really well to get it really consistent, the bugs, for example, that land on a chicken bone that had a bit of flesh on it will be different in size versus the bugs that got put on a green banana peel, purely because it makes so much of a nutritional difference - bugs love meat and perform better when a primary protein source is included in their feed. Even half a day of feeding on a subpar substrate makes a huge difference because they go from less than one millimeter when they're hatching, to 2.5 centimeters 15 days later. For that reason it's so important to make sure that everything is ground and mixed. Those particle sizes have to be really small, so that it's easier for the bugs to get at it, because at the beginning of their lives they are so small and their mouths are tiny. The easier you make their work, the better the results are down the line.

The major takeaway is that if you intend to use coffee pulp as part of the feedstock, you want to make sure that the other part of the feedstock is pretty rich in nutrients and the particles are very small and well mixed.

When feeding the larvae, are there any leftovers, or do they simply eat everything?

Well fed Black Soldier Fly larvae

To get the best results, the idea is to feed them a little bit less than what they need, that way they are forced to eat everything in the trays. The power of their manure, or frass, is that it is a really high nutrient, organic, humus-like fertilizer. As a result the amount of fertilizer that you have to put onto your trees or your plants is so much reduced because of that high quality.

Now, if you have undigested food left in there it's not the worst thing in the world, but it doesn't create this beautiful, fine fertilizer soil that you can get when everything is consumed. When you harvest the larvae, under normal circumstances nothing is left other than the larvae and the frass. Half of the feed is going into the growth of the larvae, the other half is on the trays: out of that remaining 50% the larvae themselves make up about 20% and the frass makes up about 30%. This makes the bugs an incredibly efficient waste management tool.

We've actually just worked with a company called "Footprints Africa" who've looked at the carbon benefits of the Black Soldier Fly (BSF) farming, in other words the net benefit to the environment from using BSF. We really can transform organic waste, whether it’s coffee pulp or something else, from being a carbon drain and carbon contributor to the environment, into something positive like organic fertilizer, and not to forget: protein! These bugs are really magical.

But the feed, as you said earlier, has to be the right mix. One reason why coffee pulp has to be mixed with other organic waste is the tannin content in the pulp. What about caffeine?

I think that caffeine can also be seen as a bonus. There's research that supports that the bugs are active after eating spent coffee grounds. The same logic would apply that caffeine stimulates them to be more active and therefore, eat more in a day which is the goal. But again, it comes down to that diet balance because we need to make sure that they're not overstimulated.

Assuming they are not overstimulated, how long do you have to feed the larvae until you can harvest them?

We found it took around 8 to 10 days, depending on the climate conditions. Climate being temperature and humidity play a big role in the performance of the insects. As we are in a greenhouse, the climate is very good, but during the rainy season things do take a little bit longer.

The eggs will be in the nursery for five days, and there they are given quite a beneficial diet, because it's much like a chick, let's say. You want to feed that chick really beautifully, so that it has the potential to become a really good livestock contributor. The same theory applies here, you feed a beautiful diet for the first five days of life to set them up for success in their lives, and then from there they get put into what we call a "fat camp". In the "fat camp" they get fed with these mixed substrates including coffee pulp where they then get super big and fat. We harvest them after 10-14 days.

What's the next step in their development?

So at this point, they are at what we call instar five, which is the fifth larval phase where they are still white and are their highest protein content. That's when they get harvested out and the bugs that will go to market get dried and sold. The guys that are going back into the mother colony will actually stay in the feed a little bit longer and move into a pupation phase where they start to convert and develop their “cocoon” and ultimately emerge as a fly in a couple of weeks. These flies will mate in “Love Cages” and lay eggs to continue the cycle and next generation of waste converting bugs.

What a life! First you are well fed, then you take a rest, and from there you go straight into the love cage! A short, but obviously not a bad life! How long did it take to figure out how all this works?

Oh, I've been playing with these bugs for over four years now! We still learn new stuff, and they make idiots of us all the time. We find it super exciting that the body of evidence and the body of research is still so small, which means there's so much that we can still contribute.

For instance: Another project that we worked on was trialing the bugs as a way to remove Aflatoxin contaminated maize from the market in Rwanda. Aflatoxin, especially Aflatoxin B1, is one of the biggest contributing causes of cancer on the African continent every year, and one of the biggest challenges is that there's nothing you can do with the unsafe maize. Incineration is expensive and returns no monetary value back to farmers, but doing nothing means that people and their animals are still consuming this maize. So how can we upcycle it into something valuable? It's sort of the same conundrum as with coffee waste, except this is killing people.

All existing research supports that the bugs can process the contaminated maize and turn it into a protein that doesn't have Aflatoxin but we are the first to do these trials in real life circumstances. What we do is take samples of the larvae, their substrate (diet)  and frass, which were sent to Wageningen University Lab in Europe at the moment for testing. We are expecting the results before the end of the year (2022). Essentially this could revolutionize the whole way we look at Aflatoxin on the continent, which is amazing. I'm just a random person who loves playing with insects, and I did this project and that's a super cool thing. I'm not like a crazy cool scientist obviously. We partnered with crazy cool scientists (Wageningen University & Research, ETH Zurich - funded by IFC). And there's still so much that everyone can contribute, which is amazing.

How much would you be able to pay farmers for their contaminated maize?

Well, what we're actually hoping for on the Aflatoxin front is that the government mandates that if a batch of maize is known to be contaminated above human and animal safe levels, that it would be confiscated, so that there is this forced legal element to move towards public health, but that is going to take a long time, and that's where involving the private sector and setting the price for that maize becomes really important in the meantime. We have to figure out what actually would be a good price for all parties so that we, as the private sector can create a solution.

Who would have believed all of this from such a small fly, or to be more precise, their larvae! But I have some other questions; The larvae are rich in protein, to whom do you sell them as a source of protein? Who are your clients?

Protein is a big element of this solution because Kenya and Rwanda are net importers of soy making it highly susceptible to price shocks. Other than the environmental challenges associated with soy (deforestation and mono cropping) increased pricing is placing severe pressure on feed manufacturers which is forcing company closures and jeopardizing on the quality of feed that is being sold to the market. So creating locally produced, consistently priced protein in the form of larvae is truly a game changer.  

At the moment we've halted operations in Rwanda because we are planning to do a fundraise for our facility in Rwanda. In Kenya we've got a small operation which we are using to launch a sustainable pet food brand (Loop Pet Food) which is insect based and grain free (aflatoxin free), as well as working and training small-scale farmers in insect rearing.

At the moment we're not selling our bugs because all of our bugs are going into this new pet food. But based on the theory where we have a large scale facility to work with, and where we are buying this contaminated maize, as well as taking on the coffee pulp and other waste from the municipality, we would be selling the protein to local feed manufacturers in Rwanda and Kenya, and the frass, our fertilizer, to local farms.

You mentioned fertilizers. This could become an even more interesting market if we look at what's happening momentarily regarding the prices for fertilizer.

Well, the fertilizer price has nearly doubled in the past four months since the start of the Ukraine war. It's just a disaster, because we're seeing adjusted pricing in the shops already, with the price of food increasing by up to 30% in some cases, and this is on staple foods, so people are really suffering already. We're significantly reliant on imports of things like fuel (that's everyone really and impacts everything), nitrogen and chemical fertilizers, seed oils and others. We need to find ways to make things locally to meet our own demand and grow towards self-sufficiency. Otherwise, this is just going to carry on getting worse and worse and worse, unfortunately.

Black Soldier Fly larvae: from feed to protein and fertilizer

That means, activities like yours have to scale up. How can you raise your Black Soldier Flies at a scale to have a measurable impact?

We were processing about 1 ton of organic waste daily, but in order to take it to the next level, we need to scale. For that reason we want to fundraise, so that we can have a 20 ton per day facility, which means 20 tons of organic waste going in per day. We have realistic concerns about the availability of that organic waste, so that's the type of scale that we see there.

We are now setting up an outgrow model where we farm the eggs in Nairobi, for instance. Then we would send the eggs out to hatcheries, then they sell the five day old larvae to farmers, who then use all of the outputs. Giving the power of agricultural inputs to the farmer.

Again, most of the agriculture in this area is smallholder farmers. The question is how do we engage with smallholders in order to increase scale through them, as opposed to just trying to increase scale through ourselves? I'm passionate about empowering smallholder farmers because they are literally the people who are feeding us. They have the roughest time because they face the biggest shocks when it comes to price changes and climate change, and we basically hold firm on the price of what we're willing to pay at the supermarket. They are the ones who are constantly facing the strain from this. I'm basically looking at how we can empower smallholder farmers at the farm level, so that they can realize significant cost savings on the animal feed and then getting their fertilizer with help of the bugs for free. The idea is that they can farm the way they've always farmed but with a lot fewer expenses, not necessarily to earn more money. It just means that they are saving money and can redirect their income to other places, which need their attention.

Insects are farmed to get fertilizer and protein. Black soldier fly larvae protein is not yet allowed for human consumption, and the European Union just approved it for poultry and pig feed. How are the regulations in African countries like Kenya, Rwanda?

It's the same here, it's not approved for human consumption. But I think that's understandable when you consider that you can feed these bugs almost anything. Unless there is going to be some regulation regarding what you can feed the bugs in order to keep them safe for human consumption, which I think that's where we're headed, but for now black soldier fly larvae are reserved for animal feeds. The more we learn about these insects, the more we find that the consumption and use of insects is incredibly commonplace.

Another example of how we can learn to create solutions to problems that we have faced, maybe since forever, is by just applying a bit of creativity. Over the past few years we've experienced the worst desert locust infestation for decades in the Horn of Africa. My company raised funds so that we could trial the approach of using farmers to harvest the bugs for us. Then we bought the locusts from the farmers and turned them into animal feed. We harvested four tons of locusts in six weeks. Instead of spraying them with insecticide, we were creating an income for farmers as well as for us.

In the face of climate change, where Africa is particularly vulnerable, it is becoming more and more essential to try more of these “crazy” ideas. This speaks to what I said earlier that there is such a low level of knowledge and research on insects in general, and that there's so much opportunity for us to do amazing things with these insects. We just need to be a lot more open minded and share our knowledge with others. If everyone would share his or her information and knowledge, we would be able to grow these industries a lot faster. But, that's just my opinion.

I couldn't agree more. Please tell us more about your business in Rwanda where you collaborate with RWACOF, Rwanda's largest coffee exporter, and COPED, a large municipal waste managing company. How did this happen?

I have two daughters and I decided I wanted to start working again but I could only get comfortable with the idea when I settled that I wanted and needed to do something that would make the world a better place if I was going to justify being away from my girls. As you said earlier, my girls are my inspiration.

I live in Kenya, and I started farming bugs out of my garage a little over four years ago. To make a long story short, my business partner at that time was moving from Kenya to Rwanda where he had a contact with RWACOF, and RWACOF told him: “Look, we have this huge problem with this coffee pulp, it is such a waste. We need to find a way to turn it into something valuable, or if not valuable, at least less detrimental”.

We started doing experiments and the initial experiments were pretty promising. We went into a partnership with RWACOF which lasted for one and a half years. We turned a small experimental site into a full production unit. It was really amazing to do that, but one of our biggest challenges was then scaling up to the next size to turn the project into profitability. RWACOF had paid for all the upfront capital to begin with, to prove the concept, which we have proven.

However, to continue we needed to raise our own capital and spin out on our own with the plan to continue to use their waste as a diet for the bugs. And unfortunately, our timing was a bit misaligned which resulted in our ceasing operations (for the moment).  

To scale up you need coffee pulp not only during a harvest season. How do you deal with that?

Working with seasonable crop waste is a matter of shifting recipes to maintain balanced diets, and storage of waste in the best possible outcomes. There is also the potential to increase scale based on the bump in different wastes to make the most of them and minimize on the storage requirements. We would essentially run a full 12 month period: three months scaling at the front end, then three months at the back end leading into the other coffee season. But there would be a 6 month period where we would have to shift the recipe slightly based on the availability of ingredients.

In between two harvests?

Yes, but that in itself is not a huge challenge, and actually the coffee season is becoming pretty unpredictable here because of the shifting rain patterns. The coffee season was meant to stop in December here, but the coffee only got harvested in February/March because the rains were so late. I do think that what we know about seasons is going to make fools of us, reminding us who's boss.

Wise words! But tell me: did you try to feed the larvae also with the husk of sun dried coffees?

We haven't played with that yet. But if you can grind it down into a powder, I can't imagine why that couldn´t be turned into a feedstock.

Laura, there are still so many questions! But I would say we leave it here and recommend that everyone who wants to know more about the fascinating Black Soldier Fly farming can contact you directly. The phone number and email address are on your website. Thank you so much for this very informative and interesting interview!