The secret of mushrooms at Fuorisalone

The fourth episode of Star Trek Discovery featured the spaceship “Mycelium Spore Drive” that could hop from one part of a galaxy to another…

by Paola Arpino
04 October 2019
3 min read
by Paola Arpino
04 October 2019
3 min read

No… we’re not about to transport you to another dimension, but instead we’re talking about a series of structures built from mycelium, which in fact is the concealed fibrous part of a fungus, in an initiative designed by Italian architect-engineer and visionary Carlo Ratti and exhibited at FuoriSalone 2019.

The Circular Garden installation, created in conjunction with Eni to mark Milan’s Design Week, is located within the Orto Botanico di Brera botanical garden. It examines the theme of the circular economy through the use and recycling of raw materials in a way that blends seamlessly with the natural beauty of its surroundings. The sustainable concept involves using the mycelium to build large architectural structures that might be shaped by mankind but will nevertheless be returned to the land at the end of their circular journey, ready to repeat the growth cycle.

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"The Circular Garden" installation consists of elements made using mycelium

The ‘circular’ installation is part of the Human Spaces exhibition (8-19 April 2019) – supported by Interni magazine and staged at the Università degli Studi di Milano, the Orto Botanico di Brera and the Audi City Lab – architecture elements produced entirely from mycelium. Carlo Ratti’s project is designed to showcase new natural architectural models originating from the countryside, the garden and plant matter, following a sustainable path that involve them eventually being returned to nature. The structures, which will be unveiled on 8 April, will, in fact, be dismantled and returned to their original natural context at the end of the exhibition.

The structures are created using the inner part of the fungus, known as the mycelium, which is itself made up of fine interwoven fibres known as hyphae. The hyphae, which can only be seen using a microscope, join together to form the actual body of the fungus that lies hidden in the ground or in the wooden part of the tree, beneath the bark. The part we see, and indeed that we often eat, namely the sporocarp, should actually be considered the fruit of the fungus, while the plant itself is hidden from view, lying beneath a layer of earth up to half a metre deep. It is, in fact, the unusual way in which this sort of plant matter develops that makes it such a great option for creating entirely recyclable natural goods. The mycelium can grow more quickly and take on different shapes and textures depending on the environmental conditions, humidity level, temperature and carbon-nitrogen ratio.


The mycelium is a deep part of the fungus and is formed by the hyphae, an interweaving of thin filam

To create a structure from mycelium, you first have to identify an organic substrate that can provide nutrition (such as sawdust, hemp or hay), which is then injected with the fungus and placed in a mould. This allows the hyphae to grow and to expand until they fill all of the available space, eventually becoming hard and resistant. The mycelium is then dehydrated under high temperatures, resulting in an adaptable substance that can be formed into the desired shape. It takes around a month and a half to fill a 1m² mould with mycelium – three weeks for it to grow and dry and another three to dehydrate it.

When it came to creating the structures to be exhibited in the Orto Botanico di Brera, the designers at Carlo Ratti Associati and Eni called upon some of Europe’s leading experts in the field of mycology and its applications, who have contributed to Eni’s longstanding development programme for promoting the circular economy.

Eni currently operates in the bio-refinery sector, is involved in collecting and reusing used oils, is developing new solutions for producing oil from organic waste and biomass and is investing in technologies designed to improve the efficiency of the resources that are used, right throughout the product life-cycle, and in recycling materials from all sources.



After a long preparation phase, the mycelium is subjected to high temperatures and is then dehydra