Post written by Andrea Roe

 

 

We wanted to produce a sustainable pig toy. A pig toy that was carbon neutral. This made us rethink the oven-baked biscuits idea. After consulting with a research technician at Scotland’s Rural College, we were made aware of the delicacy of a pig’s constitution, so we knew we had to tread with care. My previous research on hyphae networks in forests and Cath’s on utopian architecture led us to trial mycelium. Given the right conditions this grows on grain substrates, and we were excited by the prospect of bonding grain without using other resources.

So, with a carved wooden former I visited Plastic Mouldings Ltd, in Irvine. Three weeks later 30 x vacuum formed pressed moulds miraculously arrived at my door. These were paired up and adapted to create incubators for the live and growing substrate.

 

 

Honing the brick recipe and creating sterile growing conditions proved to be challenging. My front room was turned into an impromptu laboratory. The mycelium had its own requirements. It was to be kept moist but not wet, consistently warm (through a Scottish winter), with blinds drawn and vigilant daily observation by headlamp, to spot foreign moulds. Kitted up in latex gloves, masked against the pervasive fumes of pure alcohol, constantly sterilising surfaces, pressing, weighing and microwaving grain, boiling huge panfulls of straw, it took 28 days for the mycelium to bloom. Dreaming pink bricks, beetroot powder was added which glowed magenta, but disappointingly faded once the brick had air-dried.

Using straw rather than beer mash created lighter and faster growing bricks, they were also less robust so not ideal for boisterous pigs. The beer mash that Barney’s Beer provided varied depending which beers were being produced, rye, spelt, hop and oat mixes were all trialled, causing mycelium spores to grow at different rates and in magnificent forms.

 

 

 

The process was then stopped, and bricks were exposed to daylight, stacked and dried.

The idea, to involve stock men and women in creating and designing edible structures that are specifically suited to their drift of pigs.

Next step, send a sample to the lab to test for mycotoxins…

 

 

Photography © Andrea Roe

 

Oct 20, 2020

Post written by Cath Keay

 

 

As with Carnevale, we began by discussing toys and games designed for children that might be adapted for pigs.  We mulled over building blocks that could be stacked, bead-like objects strung in chains, or interlocking construction toys, and then settled on a notched circular form which could be easily reproduced, then slotted together like a rudimentary cactus.

 

 

 

 

We tested various mixes of spent beer mash and binding agents such as cornstarch, wheat flour, potato starch and carrageenan. However, there are concerns about how safe carrageenan is for pigs, and research papers suggest that potato starch helps their digestion, so we have gone with that. The mixture requires pressure to bind the material, so we tried using a briquette maker- a metal contraption sold to convert newspapers into fuel, which proved very unfit for this purpose. We took a lead from an online video showing how encaustic tiles are made by compressing cement powder in a hydraulic press, then we approached UoE’s Engineering Department at Kings Buildings where Mark and Andy, the technicians, showed us how to put five tonnes of pressure on each biscuit.

 

 

 

 

 

 

 

 

 

Barney’s Beer microbrewery gave us a batch of mash that contained rye, and this proved to be the best mix for biscuits that retain their notched form so that they can interlock in modular chains. The rye produces more durable biscuits; able to withhold the attention of a dozen curious pigs for longer too.

We made two sizes of former and so we will soon produce a batch of smaller (funsize) Hognobs using wheat and rye mix. We will then test both versions with the pigs at Gorgie Farm and document the pigs’ reactions to these enrichment objects.

 

 

Photography © Andrea Roe

Oct 31, 2019