This article is part of: tools.
Why do we need moulds to make tempeh? ↓
3D printed moulds ↓
How to 3D-print your own tempeh moulds ↓
Silicon moulds ↓
3D printed moulds v0.2 ↓
Why do we need moulds to make tempeh? ➹
Traditional tempeh is often produced in Indonesia using Hibiscus leaves (for tempeh starter production) or Banana leaves (for tempeh production). In our western countries, sealed polyethylene pouch (=freezer bags) are more often used. Indeed, an appropriate packaging is important as it provides optimum oxygen supply, right level of humidity and temperature for inoculation and fermentation to occur during processing. But we want to implement a reusable method to produce tempeh.
3D printed moulds ➹
The design is pretty simple, but smooth and balanced. It consists of a ~120x80x30 mm container (3mm of thickness) with a lid. There are small perforations all around the container and on the lid to allow the tempeh to breath during the fermentation process. The lid has notches to hold two rubber bands to keep the soybeans compacted inside. And the bottom part of container has a removable coin to easily remove the tempeh from the mould after incubation.
With these constraints put together, several forms can follow. We have for now, a rectangle, a zigzag and a stackable round mould.
We use FreeCAD, an open-source parametric 3D modeler that you can download for free, to design our mould. Parametric modeling allows you to easily modify our design by going back into our spreadsheet and change the values in milimeters.
Here are the sources of:
- the rectangle tempeh mould V1 (stl file and freeCAD file)
- the zigzag tempeh mould v1 (stl file and freeCAD file)
- the round stackable tempeh mould v1 (stl and freeCAD file)
available on github and wikifactory
How to fabricate the moulds?
Please, read our article to know how to 3D-print your own tempeh moulds.
How to 3D-print your own tempeh moulds ➹
Distributed Design and Decentralised Fabrication
We want our tempeh moulds open-source and easy to anyone to replicate and we allow peer reviews to make sure everyone agrees on how things are done.
We therefore use the principles of distributed design and decentralised manufacturing for the tools we make. Which means that you can download our models, review and adapt them, and produce them yourself.
The Fabrication of our moulds
Our moulds are 3D printed with our Prusa Mini with PETG filament from Prusament
We use PETG filament because the material is food grade but we realised that printing this material in 3D does not guarantee a food grade object because the hollows between the printing layers become a nest of bacteria that is difficult to clean.
Either a top coat would therefore be necessary or just ensure that the part is thoroughly cleaned, sanitised and verified clean prior to use. Before using our moulds, we first wash them with dish soap and dry them with a towel, then disinfect them with 70% alcohol and a cotton cloth.
Instructions to do it yourself
- PETG or PLA filaments should be food safe.
- Beware, potentially safe filaments might contain unsafe pigments, check it twice with your supplier.
- You should make the surface as smooth as possible. Unfortunately, this cannot be done properly with chemical smoothing.
- So 3D print the moulds at the lowest feasible layer height, we recommend 0,10 mm of layer height with an infill of 100%.
- Use a stainless steel nozzle.
- Keep your printer and printing environment as clean as possible.
- If, like us, you have a PTFE tube in the extruder, the temperatures do not exceed 240°C.
Please, find more details through those guides from Prusa and Formlabs
Silicon moulds ➹
Work in progress
These moulds are currently being designed, fabricated and tested. What you see here is relatively temporary and subject to change. This is still experimental.
Documentation page for the fabrication of our silicone tempeh moulds. These silicone moulds are supposed to be an improved version of our 3D printed moulds. They use the same model but are first moulded in a block of wax and then cast in food grade silicone. This would allow us to increase our production speed while guaranteeing high quality.
- Silicon moulds v0.1 29/07/2021
3D printed moulds v0.2 ➹
In the context of the Hyper Global / Hyper Local exchange programme, we teamed up with Valentina from My Vegan Fam to improve our tempeh moulds.
Let us introduce Valentina
Valentina is a professional tempeh maker based in Amsterdam. She has a burning passion for tempeh and that pushes her to get out and spread the love for this fantastic food. She is the one who gave us her tempeh recipe when we were in Amsterdam two years ago.
She tested our moulds and give us feedback, we then co-designed the next version and finally, we supported her to 3D print the new version in a local makerspace in order to test the distributed design and decentralised fabrication side of the project.
- We have decreased the thickness to 2mm.
- We have increased the number of holes and their diameter.
- We have abandoned the stackable version because it causes the tempeh to overheat during incubation.
- We also have designed a larger model (10x15).
- We have explored other materialities (silicon) that has its own article.
Here are the sources
- the 8x12 rectangle tempeh mould V02 (STL and Fusion360 file)
- the 10x15 rectangle tempeh mould V02 (STL and Fusion360 file)
Available on github
How to fabricate the moulds?
Read our article to know how to 3D-print your own tempeh moulds.