The Challenge

The United Nations Food and Agriculture Organisation estimates that around one-third of all food produced globally is lost or wasted each year (FAO, 2013). About 13% of food is lost in the supply chain from harvest to retail, with a further 19% wasted at the consumer, retail, and food service stages (FAO 2022). In Ireland, approximately 835,000 tonnes of food waste were generated in 2023 (EPA, 2023) Reducing food waste is critical, especially given that between 638 and 720 million people faced hunger in 2024. (FAO, 2025).

Food waste not only represents wasted food but it also contributes significantly to resource depletion and greenhouse gas (GHG) emissions, generating 8–10% of GHGs globally (UNEP 2024). If food waste were counted as a country, it would be the third-largest emitter in the world (EDGAR 2024).

A Circular Solution

Monaghan Mushrooms, a family-owned Irish business with over 40 years’ experience, is one of the largest mushroom producers worldwide. The company operates farms, packhouses, substrate production sites, and offices across Ireland, the UK, the Netherlands, Germany and Canada.

Monaghan addresses food waste and resource efficiency through a comprehensive circular economy approach. They produce their own mushroom substrate (the growth medium in which mushrooms grow) from materials like straw, horse manure, poultry manure, and gypsum. These are by-products from other agri-industries such as cereal crop production, poultry production and the horse stable industry (Monaghan, 2024). After harvest, the spent substrate is reused as a soil conditioner, closing the loop sustainably. Notably, Monaghan is the first UK and Ireland producer to cultivate peat-free mushrooms, eliminating virgin peat from their substrate mix, switching instead to fully recycled natural materials. Peat extraction for mushroom substrate damages peatlands, which are crucial natural carbon sinks and reservoirs of biodiversity. This innovative change reduces carbon footprint and improves product quality with firmer, longer-lasting mushrooms (Monaghan, 2024).

The company employs state-of-the-art environmental control systems to optimize growing conditions while maximizing energy and water efficiency. Their Irish sites purchase green electricity, with the Tyholland farm installing solar panels to further reduce reliance on the national grid (Monaghan, 2024). Rainwater capture systems help alleviate pressure on water resources, and biodiversity is promoted with initiatives like insect hotels and wildflower areas integrated into farm lands (Monaghan, 2024). Packaging innovations include a transition to recycled PET plastics, sustainable cardboard trays, removal of colourants to aid recyclability, and phasing out PVC films in favour of polyethylene alternatives (Monaghan, 2024).

Climate Impact

Monaghan has achieved a 17% reduction in energy use per tonne of mushroom produced, aiming for further cuts in the upcoming years (BIOrescue Consortium, 2019). Over the past year, the company exceeded its energy-reduction target by 13% across its Irish sites by installing LED lighting and innovating cooling technologies that use fresh air rather than mechanical cooling (Monaghan Mushrooms, 2024). These improvements contributed to an 8% decrease in direct carbon emissions. Through solar PV adoption and green power purchasing, Monaghan decreases its demand on carbon-intensive energy grids further supporting decarbonisation (Monaghan Mushrooms, 2024).

Alongside environmental gains, Monaghan’s partnership with UK food redistribution charity FareShare has provided over 1.3 million meals to people in need since 2017, preventing food waste and associated emissions, while reinforcing social impact (Monaghan, 2024).

Replicability

The global mushroom market was valued at USD 54.9 billion in 2022 and is expected to surpass USD 115.8 billion by 2030 (Kerry Group, 2023). Mushrooms require minimal space, energy, and water, making them well-suited to sustainable intensification in food production. Rich in vitamins, proteins, and antioxidants, mushrooms now serve growing consumer demand in health, wellness, pharmaceutical, and personal care sectors (Kerry Group, 2023).

Monaghan’s circular model—combining sustainable substrate production, resource-efficient farming, innovative packaging, and community engagement—offers a replicable blueprint for agricultural industries seeking to transition to circularity. Its reliance on agro-industrial by-products and smart energy systems demonstrates industrial symbiosis in practice.

Additionally, Monaghan’s innovation division, mBio, exemplifies circular innovation by leveraging mushroom mycelium to develop bio-based materials and nutraceuticals, expanding mushroom-derived products beyond food into construction, packaging, and health supplements (mBio, 2024)  This diversification highlights the potential for circular research and development to create new economic and environmental value streams within agri-food ecosystems.

Other companies tackling food waste include:

• Meade Farm (Ireland) valorises surplus and “non-table grade" potatoes by converting them into premium food-grade starch, significantly reducing food waste and creating a new revenue stream.

  
  

• Well Spent Grain (Ireland) divert brewers spent grain from landfill and turn it into ‘Honest, Delicious, Sustainable Snacks.’

  
  

• Toast Ale (UK) produces beer brewed with leftover bread from bakeries to reduce food waste while fostering social enterprises.

  
  

• Winnow Solutions (Global) offers smart kitchen technology to monitor and reduce food waste in commercial kitchens by providing real-time data analytics.

  
  

• Renewal Mill (USA) recovers nutrient-rich by-products from food manufacturing, like okara from tofu production, and repurposes them into flour and baking ingredients.

  
  

• Full Harvest (USA) operates a platform to sell surplus and imperfect fruits and vegetables to food and beverage companies, reducing farm-level food waste.

  
  

These companies demonstrate diverse approaches—waste valorization, ingredient upcycling, technological innovation, and marketplace solutions—showing the breadth of circular economy practice in food. They offer useful analogies and potential partners for Irish food and agri-business stakeholders aiming to scale circular solutions.