MANGO BIOLEATHER

GENERAL INFORMATION

“Flexible leather-like sheet made from overripe mangoes. The material is thin but emulates the feeling of leather quite well but feels a little dryer to the touch than leathers used in most clothing items and accessories. It is translucent unlike leather however. Its natural color is amber/orange (but can be dyed), and it keeps a lovely mango smell” Loes Bogers.

This recipe template was developed by Loes Bogers, as a part of her final project in Fabricademy 2019/2020.

Physical form

Solid / Surfaces

Color without additives: translucent, yellow/orange/brown.

Fabrication time

Preparation time: 1 Hour

Processing time: 1 week

Need attention: Ideally needs about 14 hours of drying at low temperature in the oven 40-50 degrees fan setting). Then 5 more days alternating air drying with pressing (every 8 hours). If the weather is dry and sunny, the drying process can be much faster by laying the material outdoors during sunny hours.

Final form achieved after: 7 days

Estimated cost (consumables)

0,21 Euros for a yield of approx one 25x25 cm sheet

RECIPE

Ingredients

  • 2 Overripe mangoes - with skin get these as waste from the market, they can have dents and bruises it doesn't matter.
  • 1 lemon
  • Beeswax: 20g
  • Cinamon: 1 teaspoon

ingredientsRecipe mis en place, Beatriz Sandini, 2020

Tools

  1. Cooker or stove (optional: temperature controlled)
  2. Pot
  3. Blender or stick mixer
  4. Scale
  5. Oven or a Dehydrator machine that can go as low as 50 degrees (or ideally 40) with ventilation
  6. Mould or flat surface you can cast the fruit leather into a shallow mould with wals (need not be higher than 5 mm) or cast directly onto a smooth sheet. Applying some oil helps to release it. Make sure it fits into your oven
  7. Spoon or squeegee

Yield

Approx. 40 x 35 cm sheet of 3 mm thick

Method

  1. Preparation

    • Cut the mango into smaller pieces and puree it in a blender or with a mixer
    • Cut the beeswax in smaller pieces
  2. Mixing the ingredients

    • put the mango puree in the pot with the lemon and wax
    • heat it at a low heat while stirring, you don't want it to boil and stick to the pot, but you want to kill any bacteria in there and dissipate some water.
    • dissipate some of the excess water if it is very liquid but keep a low heat and stir. -after 20 minutes the mixture should be thick but liquid enough to cast on a flat surface
  3. Casting and dehydrating in the oven

    • Pour the paste onto the surface or mould and spread it out evenly, knock it on a hard surface gently to even it out more.
    • Heat the oven to 50 degrees Celcius on the fan setting and put the paste into the oven for at least 16 hours (you can spread it out over a few days with air drying in between). If your oven allows it without turning itself off: keep the door slightly open with a cloth to let the moisture escape).
    • After one day out the oven, carefully peel the leather off the tray, flip it, and check if the bottom has fully dried. If not, put back in the oven with the moist side up for another few hours.
  4. Air drying

    • when the leather is dry to the touch (it will be a bit darker of color now), let it air dry in a well-ventilated space for another 5-7 days.
    • alternate drying and pressing under a stack of heavy books or dry on a roster with weight on top for further drying while keeping it flat.

Drying/curing/growth process

  • Mold depth: 3 mm (using acrylic borders)
  • Shrinkage thickness: 50 %
  • Shrinkage width/length: 5%

Shrinkage and deformation control

Letting it dry up to 7 days to get to the final form. Mango leather tends to dry at a different pace every time, depending on the amount of juice and amount of dissipating. This is a slow process. Trying to demould too quickly will damage the leather.

Curing agents and release agents

Some oil helps to release from the mould.

Minimum wait time before releasing from mold

2 days

Post-processing

Trim frayed edges and cut or slice into desired shape before the slab is completely dry and hardened to obtain the best results.

Store in a dry space. Baking paper between sheets prevents sticking. Some suggest using desiccants to keep the sheets dry (e.g. sprinkling starch onto the sheet).

Further research needed on drying/curing/growth?

Some more experimentation could be done on the effect of dissipating more or less water before drying, and adding more starch. Some post-treatments could be experimented with to make the leather more waterproof (see also "variations on this recipe").

Process pictures

via GIPHY

Casting with the help of a squeegee, Beatriz Sandini, 2020

Material after drying in the oven, Beatriz Sandini, 2020

Variations

  • Add a natural colorant such as a vegetable dye or water-based ink (e.g. hibiscus, beetroot, madder). The puree is acidic (PH6-7), consider this in your choice of colorant. Dissipate some more water or to compensate for the added liquid. Adding spices may also work to create color (and smell variations).
  • Stiffeners such as fibres, yarn or natural debris may be added for more structure and reinforcement.
  • Try other fibrous fruit waste like, apples, pears, peaches, plums or even rhubarb.

Tapioca Starch Variation

Ingredients

  • 2 Overripe mangoes with skin : about 400g
  • Tapioca Starch : 23 g
  • Vinegar: 23 g
  • Salt: 5 g
  • Beeswax: 20g

This recipe is also a variation form the potato starch based recipe from Loes Bogers. The same tools and method described there can be followed for this recipe variation.

Yield Approx. 40 x 35 cm sheet of 3 mm thick

ORIGINS & REFERENCES

Cultural origins of this recipe

Fruit leather was originally conceived of as a way to preserve fruit and is eaten as a snack! It's a way to preserve fruits, which is especially handy in hot climates where fruit is abundant but ripens and spoils ever so quickly. To make fruit leather, overripe fruit is best, used with skin and all.

"T'tu Lavash" for example, is "sour lavash" (lavash is flatbread). An Armenian specialty often made from apricots, which is the national pride. It's pureed and the pulp is dried on sheets of cardboard. It is also called called pastegh or bastegh. Similar fruit leathers are called "tklapi" in Georgia, "lavashak" in Iran, "pestil" in Turkey, and "amerdeen" or "qamar el deen" in Lebanon, Syria, and other Arabic-speaking countries. It has become very popular recently as it preserves a lot of the nutrients of fruit, without needing any additives: it has become a healthy snack for conscious eaters.

As a design material it has gained a lot of recognition from the development of fruit leather as an alternative for mammal hides and leather tanning practices, which is considered heavily polluting and cruel to animals. Rotterdam Leather is a start-up based in the Netherlands that recognized the local waste stream of market fruits: 3500 kgs are thrown away after an average market day, vendors have to pay to dispose of this waste. Rotterdam Leather now sells technically tested fruit leather as design material commercially, and can produce up to 50-70 square metres a month.

This section is attributed to Loes research and documentation

Needs further research? Not sure

Key Sources

Several snacks fruit leather recipes online. Later merged them with the starch based ones.

Recipes are published under a Creative Commons Attribution Non-Commercial licence.

ETHICS & SUSTAINABILITY

Fruit leather as design material can only exist with the grace of excessive food waste. We should consider if we should make it easier to dispose of food waste at all or try to eliminate it. Others might argue it is better to use the fruit than to let it go to waste.

Moreover, if you live in northern Europe, you should consider mango's to be exotic fruit. So first they are shipped long distances, only to be thrown away. This is an issue that needs to be addressed, not celebrated.

Some climates might be too cold for a natural drying process, so it will involve more time to produce, and/or more energy to use ovens and dehydrators, like described in this recipe.

This section is attributed to Loes research and documentation

Sustainability tags

  • Renewable ingredients: yes
  • Vegan: yes
  • Made of by-products or waste: yes
  • Bio Compostable final product: yes
  • Reuse: needs further research

Needs further research? yes, possibilities of re-using the leather

PROPERTIES

  • Strength: medium
  • Hardness: flexible
  • Transparency: translucent (varies from fruit to fruit)
  • Glossiness: matt
  • Weight: medium
  • Structure: closed
  • Texture: variable (if dried on acrylic one side will be smooth)
  • Temperature: medium
  • Shape memory: medium
  • Odor: moderate (but a nice mango smell)
  • Stickiness: medium (can get sticky easily with moisture)
  • Weather resistance: needs further research
  • Acoustic properties: needs further research
  • Anti-bacterial: needs further research
  • Non-allergenic: needs further research
  • Electrical properties: no
  • Heat resistance: low
  • Water resistance: low
  • Chemical resistance: needs further research
  • Scratch resistance: medium
  • Surface friction: medium
  • Color modifiers: none

ABOUT

Maker(s) of this sample

  • Name: Beatriz Sandini
  • Affiliation: Fabricademy student at Waag Textile Lab Amsterdam
  • Location: Amsterdam, the Netherlands
  • Date: 20-02-2020 – 10-04-2020

Environmental conditions

  • Outside temp: 5-17 degrees Celcius
  • Room temp: 18 – 22 degrees Celcius
  • PH tap water: 7-8

Recipe validation

Has the recipe been validated? Yes, By Loes Bogers, Fabricademy student at TextileLab, Waag Amsterdam, 2 April 2020

Images of the final sample

Mango Tapioca Variation, Beatriz Sandini, 2020

Small sample of mango leather, made out of 1/3 of a mango (lemon, beeswax and cinammon follows the same ration as main recipe), Beatriz Sandini, 2020

Small sample of mango leather, made out of 1/3 of a mango (lemon, beeswax and cinammon follows the same ration as main recipe), Beatriz Sandini, 2020

References

  • T'tu Lavas by Susie Armitage for Gastro Obscura: link
  • Rotterdam Leather link
  • Fruit leathers (Practical Action Brief) on Appropedia, link