HOW (Household Organic Waste),
a participatory material

Abstract

This study in a nutshell

Looking at the world as it could be...

Let's imagine that HOW (household organic waste) is commonly seen as a renewable resource (which it actually is, by the way). HOW is valuable; it is an object of desire in a world of scarce resources, so it is not thrown away just like that. We all produce it: we crowdsource HOW. In this scenario we have to rethink our relationship and behaviours around it. The moment HOW begins to have trade value, it also begins to have social and political weight.

The social bio-tech proposition:

We look at HOW as a social catalyst: engagement with it helps engagement with sustainability. We are working towards shifting HOW from waste into renewable resource. The proposition is that HOW needs to go through controlled biotech processes just as much as it needs a new place and meaning in our minds. Hence: a bioconverted HOW material obtained and used by people in their neighbourhoods.

Is a participatory HOW material possible?

As a design-science collaboration, we answer this question by empirical laboratory experiment. In the course of 6 months, 10 HOW batches undergo various treatments in different conditions to understand HOW's potential and limitations.

On the social level all laboratory experiments go through the filter of participation: if people would do this, how would they do it? Parallel to this, a survey is run with the help of 23 volunteers. Data is collected on people's current relationship with HOW, and the difficulties they experience with it right now.

On the technical level two bioprocesses involving HOW are combined and experimented with: bokashi fermentation and mycelium forming. The main focus is in finding a way to turn HOW from heterogeneous biomass into a homogeneous substrate. This is to be later used by a fungus to grow on, and create a HOW material.

In a nutshell:

It is important to first explain what we mean by (1) HOW, (2) participation, (3) bokashi fermentation, and (4) mycelium forming, and how these concepts and processes are used in the study. Afterwards we describe (5) the survey data and (6) the experiments carried out on the 10 HOW batches.

We continue with (7) the conclusions of this empirical cross-over study. The process of this paper proved to be more politically entangled than first expected, reason for which contextual difficulties are reviewed in (8) a discussion section. Finally, we close with giving (9) a glimpse of what a participatory HOW material would be like if it existed.

HOW

HOW is a heterogeneous biomass. It is simply what people throw in their bins, which means that the composition of an organic waste bin could not be recreated twice in household conditions. The main challenge of this study was to turn HOW from this heterogeneous mass into a homogeneous substrate for mycelium forming.

HOW was collected for this study in the same way it would be collected at home. Three volunteering households contributed to a total of 10 HOW batches, over the course of 5 months. Collecting each batch took between 1 and 2 weeks. In most situations, HOW already had 'guest' micro-organisms upon arrival at the lab, such as grey or green moulds.

HOW contained all organic matter possible in the household, with a few exceptions: pet and human faeces, high quantities of garden waste (such as a whole sack of leaves), seeds larger than 5mm diameter, and bones.

The general treatments HOW undergone in all 10 situations were:

1. chopping it into small pieces with a knife or mincing it in a blender;
2. bokashi fermentation;
3. drying it at 65 – 72 degrees Celsius;
4. inoculating it with mycelium and mycelium forming;
5. final drying at 65 – 72 degrees Celsius.

HOW Categories

Upon observation throughout the study, HOW was classified in 6 groups of substances:

1. hard fibres (rich in cellulose);
2. coffee and tea;
3. fruits and vegetables – soft peels and pulp (rich in simple sugars);
4. animal waste;
5. citrus fruit and peels;
6. starches (rich in carbohydrates).

Participation

To explain participation we look at two aspects:

1. the path taken in developing a HOW material;
2. the participatory features of this material.

This study is the path taken in developing a HOW material. In order to create a material that can be later replicated by people in a DIY manner, we ran lab experiments. The bioprocesses involved (bokashi fermentation and mycelium forming) were tested for safety, error margins, and limitations. The focus was laid on the likelihood of non-professionals to conduct these processes on their own, outside the lab. Hence, lowest threshold type of involvement was key; if people would do it, how would they do it? We called this “searching for a participatory method”.

In the lab, scientific knowledge was adapted for participation by:

1. using heterogeneous HOW compositions from actual households;
2. taking the precautions to diminish long contact between HOW and the human body: chopping or mincing and using adapted containers;
3. making Bokashi fermentation as easy as possible;
4. using different mycelium proportions when inoculating HOW to test error margins in the process.

Participation as referred to in the title addresses the features of the HOW material in practice, once a participatory method would be in place. This means the capacity and willingness of citizens to collect their HOW, obtain the material in their neighbourhoods, and use it locally.

The part of the study carried out so far focuses on the question:

Is a participatory HOW material possible?

This means that the exact participatory features of the HOW material are not discussed yet.

Bokashi fermentation

Bokashi (translated from Japanese “well fermented material”) is known worldwide as a DIY practice to break down organic waste, just like composting. However, by comparison to composting, bokashi fermentation follows a different process. First of all, it is faster; while a compost bin takes up to 1 year to break down, the bokashi process takes about 7 weeks on average. Also, composting needs oxygen and frequent mixing, while bokashi fermentation happens in anaerobic (no oxygen) or semi-anaerobic (low concentration of oxygen) conditions. Furthermore, while composting degrades biowaste with release of CO2, bokashi preserves the nutrients and CO2 in biomass. This means that whatever comes out after bokashi fermentation is not compost – soil-like mass – but merely 'pickled' (and acidic) biomass. This has a specific smell (vinegary, just like pickles) and looks almost the same as the original waste, only a little bit browner. The 'pickled' biomass resulting from bokashi fermentation needs to be buried into the ground to continue to decompose.

To start fermentation, (household) organic waste is mixed with a bokashi starter. This is a microbial inoculant that can be bought in a liquid state – the product is called EM – or as bokashi bran. The inoculant contains a mixture of about 80 different micro-organism strings that live together in a symbiosis, amongst others lactic acid bacteria, yeasts, phototrophic bacteria, actinomycetes bacteria, or certain types of fungi.

In this study bokashi bran was used to ferment HOW. The proportions between the bokashi starter and HOW varied between 1:20 and 1:2. No information was available on optimal proportions for a good fermentation. Furthermore, no information could be found on the speed of fermentation when the proportions between Bokashi bran and HOW vary. Upon observation we concluded that the optimal process for our practice is 1:10, with 80% bran mixed into the HOW and the remaining 20% as a top 'sealing' layer. Anaerobic fermentation went better than semi-anaerobic fermentation, and we observed that an acceptable fermentation is anything above 5 weeks of 'pickling'. Almost all HOW was fermented in containers with liquid separators. This proved to be crucial to the process; without separation HOW would rot.

In the hot weeks of summer fermenting HOW formed thick layers of white mold. HOW batch B.2.2 was thrown away for this reason. After further reading and talking to compost specialists, we found out that white and green molds can become part of the microbial population of Bokashi. As a result, although batches B.3.1, B.3.2 and B.3.3 developed white mold as well, we continued using them.

Mycelium forming

Mycelium forming is a stage in the life of a fungus, between spore and fruiting body. Fungi are extremely diverse organisms and thus have varied life cycles, some of them not producing fruit bodies at all. They can vary from single-celled organisms to bodies that span over hectares. Many people think that fungi are dangerous, but only some of them are pathogenic.

In this study we experimented with mycelium spawned from ganoderma lucidum. Because the Queendom Fungi is so diverse, we will explain the mycelium forming of only such fungi as ganoderma, namely the mycelium of mushroom-forming fungi of the Basidiomycota division.

Basidiomycetes/Basidios have the ability to produce complex fruit bodies and are considered the most highly evolved fungi (together with the Ascomycota division). They include the majority of edible, medicinal, cultivated, wild harvested, and remediative mushrooms. They reproduce sexually, meaning that two nuclei are needed to form new life.

The mycelium of mushroom-forming Basidiomycete has multiple stages of development. After a spore has landed into a suitable habitat, this germinates to form monokaryotic (one nucleus) primary mycelium. Primary mycelium branches out in three dimensions. Each of these branches is called a hypha. The monokaryotic hypha seek a compatible mycelial network produced by another spore. As primary mycelium, a fungus can grow and survive on its own for a long time.

When two compatible mycelial networks meet, they fuse together in a process known as anastomosis. Fused, the two primary mycelia swap their intercellular fluids and nuclei, forming a network of secondary mycelium that is dikaryotic (containing two sets of nuclei).

The dikaryotic mycelium extends at the tip of each hypha. As new segments are added to the tip, clamp connections form between segments to help coordinate the replication of nuclei. At room temperature, this development is visible already after 4 – 6 hours and it starts to look like a fluffy mass.

The dikaryotic mycelium continues to grow until it runs out of food (in our case, HOW substrate) or space, or if other environmental signals trigger the formation of a mushroom (e.g. change in temperature or humidity). The mushroom is the fruit body that we see.

The mycelial networks of different fungi can vary in physical properties. The mycelial network of ganoderma lucidum grows tight and can be controlled to develop the properties of a hard material such as wood composites or Styrofoam. In this study, the ganoderma lucidum mycelium spawn contained a minimum of bran-like substrate to assure the start of mycelium forming. This was mixed in different proportions with dried fermented HOW and put to form at controlled temperatures, between 25 – 30 degrees Celsius. In section 6: HOW Batches: experiments and result all processes involving mycelium forming on HOW are described.

People and their HOW: survey and results

Throughout the months of the study, a survey was conducted. Next to the lab experiments, we were interested to find out what HOW looks like in household bins and what is people's relationship with it. Through an online open call, people were asked to

1. keep a 3-week diary of the organic waste they threw away;
2. fill in an online form.

The diary consisted of 3 sheets (one for each week), divided by day of the week. Under each day, participants were asked to list the organic item they threw away by name e.g.: celery sticks, leftover lasagne etc. Quantities were mentioned occasionally but were not directly asked, as in most cases such information is impossible to deliver.

Next to this, participants were asked to fill in an online form that would allow us to contextualise the HOW diaries. The form focused on demographic questions (size of household, education etc.), relationship with waste (Do you separate waste?), and knowledge about HOW.

The online call was shared on the social media channels and website of Studio Catinca Tilea, and on the social media channels of BlueCity. 23 people volunteered to contribute to the survey, 15 of which responded enough to the call so that their input would be useful. Only 10 of all volunteers committed to the entire survey.

All diary entries received, were organised on the 6 HOW groups relevant to this study. Soft fibres were the most mentioned type of HOW written down (46.4%), followed by hard fibres (21%), coffee and tea (11.2%), animal waste (10.8%), starches (5.4%), and citrus (5.2%).

Additional information about people's relation with waste proved to be very difficult to assess. Most of our survey respondents engaged via the online networks of BlueCity, which is the center for circular solutions in Rotterdam. They responded in surprisingly high proportions that they always separate waste and that they have no difficulty with it. This was confronting to the average reality we could gather through observation and literature (people don't easily help in waste stream collection and processing). After further discussions with the respondents, we found out that most of our participants were highly aware of topics such as climate change and were already looking for ways to participate in environmental programs. For these reasons we cannot assess here the extent to which people separate waste and how difficult this is.

However we consider relevant that less than half of our volunteers committed to the survey for 3 weeks. This can indicate that keeping track of waste is not a simple matter.

Furthermore, we consider that people may have difficulties in showing positive behaviour around HOW because they don't know much about it. This was the last question of the online form:

“Almost all household organic waste (HOW) ends up in the general waste bin. At municipal waste processing centers HOW is almost impossible to separate. For this reason, HOW is mostly buried at landfills together with other types of waste. HOW is bio-degradable when left in open air, and it needs about 1 year to become one with the earth. When HOW is buried at landfills it cannot bio-degrade (air is missing). HOW remains intact into the ground for years on end. Burying HOW at landfills together with other waste means turning HOW into a health and environmental hazard. Did you know that?”

41.2% of our respondents didn't know this, while 35.3% knew only a part of this information, and only 23.5% knew it all. When looking back at the environmental awareness of our respondents, these percentages show that HOW is not perceived as a renewable resource.

HOW batches: experiments and results

We experimented with a total of 10 HOW batches. This section is an overview of all the experiments performed on these batches, including all bokashi fermentation and mycelium forming treatments, and the ways in which these were performed. The information is organised per HOW batch. Each HOW batch is one of the codes below. When clicking on any of them you can follow the batch on a timeline, with pictures and descriptions of each experiment, and the HOW material samples resulting from it. Experiments are provided on the timeline diagrams as calender dates.

These diagrams preview all the descendent samples created from each batch and in each situation. By clicking on the blue illustrations or text (mainly on dates) you can follow the set-up, conditions, and results of each experiment.

Conclusions

We made the social biotech proposition to explore if a participatory HOW material is possible. This material would be obtained by people from their biowaste, in their neighbourhoods. The study combined a survey with laboratory experimentation.

23 volunteers offered to keep a diary of the HOW they threw away for three weeks. 15 of them provided enough usable information, but only 10 people committed to the whole period. Soft fibres were the most mentioned category of HOW present in the household bin. The next largest category was hard fibres, followed by coffee and tea, animal waste, starches, and citrus.

Behaviours around HOW were difficult to assess. However, we considered relevant that less than half of our respondents kept a diary of their HOW until the end, but also that almost half of our participants didn't know anything about the life cycle of HOW. These findings give us enough reason to continue this study.

In the laboratory bokashi fermentation and mycelium forming were used to carry out experiments on a total of 10 HOW batches. Bokashi was used to turn heterogeneous HOW into a homogeneous substrate. This substrate was then combined with ganoderma lucidum mycelium spawn and left to grow into a material. Our experiments focused primarily on assessing physical properties: size of growth, visual appearance, speed of growth, rigidity or flexibility of the material, and colour. Our main findings were:

1. mycelium needs a minimum surface of 10 cm to form;
2. the substrate has to have enough air pockets to allow oxygen through;
3. mycelium needs a humid substrate, but too much humidity increases the chances of contamination;
4. the pH of the HOW substrate matters (post fermentation pH=4; needed for mycelium forming pH=7);
5. almost all substances used to raise the pH of HOW inhibited the mycelium; (f) the optimal natural speed of forming the HOW material is 7 weeks fermentation + 2 weeks mycelium forming and end of treatment;
(g) the initial positioning of HOW and mycelium spawn influence the tensions that form in the material; as such, layered positioning led to a flat material mass as opposed to homogeneously mixed positioning creating a slightly concave surface;
6. the HOW material can be coloured if pigment is used before the mycelium forming stage.

All in all, a participatory HOW material is possible. We would want it to exist to contribute to long-term social education on sustainability. A participatory HOW material is the type of solution that happens close enough to home life that it can influence the readiness of citizens to engage with sustainability. But a participatory HOW material is also there to provide a renewable alternative to single use materials and objects. A HOW material should therefore be circular. This is a point of improvement in the method developed so far. Obtaining this material still needs adjustments on the use of energy. As such, our method needs to be further refined by (a) using a fungus more adequately forming on acidic fermented HOW and by this (b) eliminating a large amount of energy used in sterilising the material several times.

Circularity in everyday life

The contribution of this study to social knowledge and practice is a method that makes people ready to act sustainably. Trying to involve communities in the process requires having and sharing access to knowledge.

Along the way, this study was hindered by political and economic aspects that relate to ownership of knowledge. Not only did these aspects delay results, but they also brought another problem to the forefront: it is almost impossible to exist for small scale creative solutions that try to reimagine the world. We aspire to a world in which circularity is part of everyday life. However, we should not forget to see that the way we distribute power right now only makes this world into a distant dream.

Who owns the world?

In this study two biotech practices were explored, both known to have at least associations to DIY culture:

1. bokashi fermentation, sold as a DIY product and targeted at amateur gardeners;
2. mycelium forming, a process expected to change our relationship with waste.

These biotech practices were attended to non-standard, outside of their marketed features. Bokashi was used to ferment HOW into a homogeneous substrate for mycelium to form on it; mycelium would then form into a HOW material. The main difficulty was in using HOW as a substrate.

Literature about the microbial composition of bokashi starters is either unavailable or contradictory. As we've encountered troubles with fermentation (abundance of white mould or no sign of the starter working), we reached out to the main bokashi distributor in Europe. Their scientific board couldn't explain any bokashi features to us because of patent restrictions. Further, the possibility of trying different mycelium spawns for our acidic substrate was discussed. After consulting with two of the largest fungal labs in Western Europe, we've learned that such fungi are patented and even their names cannot be disclosed. In short, any extensive scientific information on our bioprocesses was unavailable, even if it was made clear that this information wouldn't be used for commercial purposes.

This limited our experiments and delayed our results. It is absolutely legitimate for research groups to protect their findings from theft. However, a social anomaly appears when information sits so tight under a price tag that it never comes out of the box. It is evident that integrating sustainability into everyday life is urgent. So, let's rethink who is allowed to contribute to social improvement and who isn't. Segregating science under market capital is doesn't look like a long-term solution.

Are we in this together, or not?

It is possible to integrate circularity in everyday life. However, the challenge in designing this is larger than any discipline alone can contain. We have trouble picturing a circular world in which we all act sustainably because we constantly try to adapt new ideas to old systems. This makes all ideas merely a small band-aid on a giant wound. Picturing circular everyday objects means looking at all steps between extraction of resources and post-consumption recycling in the life cycle of an object, simultaneously. This involves keeping track but also interfering on hundreds of levels, all situated all over the world, and with different economic objectives.

It's time to forget about sustainably labelled patchwork and start designing new systems. We can do this by increasing collaboration, social intervention, and educational solutions. Sustainability should be the base of a healthy social system. If we cannot solve this on our own, the least we can do is to pass on our knowledge in full to next generations.

The day the participatory HOW material is there

We all produce HOW. It is desirable that we wouldn't in the future, but to get there some in-between steps are needed. Thus, let's imagine that the participatory HOW material is already there.

Every household is provided with a green bin. This can be emptied out somewhere within walking distance from home. The green bin contents go into the collection chamber of a machine similar to a bioreactor. Inside of it, HOW is put through fermentation and mycelium forming and becomes sheets of HOW material. This transformation is a visual spectacle on its own. Also, a HOW processing facility is like a playful neighbourhood factory. It requires engagement by 'feeding', but also by keeping the bioprocesses running.

It is not expected that everybody would volunteer to engage with it. However, for those who do, there is a reward system in place. Every time you throw HOW in the fermentation chamber or aid the biotransformation processes, you receive points. These points are exchangeable for sheets of HOW material. This stimulates collaboration within the community: one's points can be collected for oneself but also for others, or for the neighbourhood itself. Engaging with the participatory HOW material also makes people aware of HOW's properties and the amounts of HOW each household produces.

This study explored the possibility of developing this material. We now know this material is possible and it can contribute to environmental education. In order to make this into our reality, studying the participatory HOW material should continue.

The next step of research is to optimize the biotransformation process of HOW and make it energy neutral. After this stage, the playful neighbourhood factory would be designed. A third step would then be to implement this method in one test neighbourhood, after which the method would be perfected upon observation. This future is within reach.

Colophon and acknowledgements

Studio Catinca Tilea
HOW (household organic waste), a participatory material

Studio Catinca Tilea is a multidisciplinary design practice based in Rotterdam, The Netherlands.
www.catincatilea.com
hi@catincatilea.com

Edited by: Catinca Tilea
Assistant editor: Teun Verwijs
Copy editing: Weronika Rybarczyk-Jósko, Stefan Blokker, Nicole Bettonviel
Scientific support: Emmy Jaarsma
Scientific advisors: Weronika Rybarczyk-Jósko, Maria Briglia
Graphic and web design: Cristina Cochior
Production: Catinca Tilea, Teun Verwijs
Photography: Studio Catinca Tilea
Illustrations: Studio Catinca Tilea, with exception of section 4. Mycelium forming

Independent publication: No part of this publication may be used or reproduced in any matter whatsoever without written permission except in the case of brief quotations embodied in critical articles and reviews.

Published online in The Netherlands. 30 January 2020
© Copyright 2020, Studio Catinca Tilea

Acknowledgements: Studio Catinca Tilea would like to thank to all contributors and scientific advisors who supported this study: Sabina van der Spek, Esther Drescher-van der Steen, Priscilla Ramrattan, Anne-Wil Hop, Inge Broers, Meng Li, Berthe Veltkamp, Marco Signoretto, Alexandra Sorina Dan, Anke van de Dries, Oana Clitan, Willemien van Musschenbroek, Laura van der Vlis, Matheus Matioli, Moe Sasaki, Zalán Szakács, Anna Hanchett, Edoardo Verderone, Andrea Foschiatti, Gail Heffner, Laura Arkana, Caroline de Vlaam, Bij de Oorspronk, Nick van Biezen and Nienke Binnendijk.

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