Sustainable catering in London means more than a recycling bin by the kitchen door. For us, it starts with the produce we buy. Since 2025 Mayfair Catering has sourced surplus and “wonky” fruit and vegetables through Angry Monk, our wonky veg rescue partner. Each month they send us an independent impact report that measures what our orders actually achieved. The September 2026 report is our strongest month yet. Here is what it shows.

September 2026 at a glance

• 404 kg of surplus produce rescued: good fruit and veg that would otherwise have been thrown away
• 501 kg of CO2e saved: the same as driving 4,096 km in a car, or a year of carbon absorbed by 20 trees
• 196,601 litres of water conserved: about 1,638 ten-minute showers
• 96 meals donated through the partnership
• 98 items ordered across 6 deliveries to our venue kitchens

That works out at roughly 94 kg of surplus food rescued and 117 kg of CO2e saved every week of the month.

Why surplus produce matters for sustainable catering

Food waste is one of the most overlooked sources of emissions in hospitality. A vegetable that is grown, harvested and transported but never eaten still carries its full carbon cost. These are its “embedded emissions”. If it is then sent to landfill, it rots and releases methane, a greenhouse gas that Angry Monk’s methodology puts at 28 times more warming than carbon dioxide.

Water is the hidden cost. Angry Monk uses an average of 322 litres of water for every kilo of vegetables and 962 litres for every kilo of fruit, based on Water Footprint Network and World Economic Forum data. Less than 1% of the world’s water is fresh water available for people to use. So when we put a misshapen carrot or an oversupplied crate of tomatoes on the menu, we save that water as well as the food.

Angry Monk watches London’s wholesale markets and growers for produce at risk of going to waste, usually because of how it looks or because there is too much of it, and passes it on to chefs. The quality on the plate is the same. Only the story behind it is different.

Venue by venue: where the savings came from

1 Basinghall Avenue, City of London

September was the first full reporting month for our kitchen at 1 Basinghall Avenue, and it made a strong start. The venue rescued 346 kg of surplus produce, saved 436 kg of CO2e and conserved 177,925 litres of water. It also accounted for 82 of the month’s donated meals. If you are planning an event there, take a look at the meeting and event spaces at 1 Basinghall Avenue.

The Minster Building, Mincing Lane

At The Minster Building we rescued 58 kg of surplus produce in September, saving 65 kg of CO2e and 18,676 litres of water, and donated 14 meals. Since we started reporting in May 2025, the Minster kitchen has rescued 171 kg of produce and saved 204 kg of CO2e. The building’s conference and event spaces in EC3 can be booked through Cavendish Venues.

Hallam Conference Centre, Marylebone

Hallam Conference Centre on Hallam Street has been part of the programme since June 2025. To date it has rescued 207 kg of surplus produce, saved 272 kg of CO2e and conserved 75,166 litres of water. Its conference rooms in Marylebone can be booked through Cavendish Venues.

The running total

Across our three reporting venues, Mayfair Catering has now rescued 724 kg of surplus fruit and vegetables. That has saved 912 kg of CO2e and 316,148 litres of water, and donated 172 meals. Most of it has come in recent months, and we plan to keep growing it.

How the figures are calculated

We do not produce these numbers ourselves. Angry Monk developed its methodology as part of The Greenhouse accelerator at Imperial College London, working with the Centre for Climate Change Innovation. Carbon savings are calculated item by item, because every type of produce has a different footprint. The everyday comparisons use published sources:

• Car km: 0.122 kg of CO2e per km (GOV.UK)
• Trees: 25 kg of CO2e absorbed per tree per year (Ecotree)
• Showers: 120 litres per ten-minute shower (Waterwise)
• Toilet flushes and laundry cycles: 5 litres and 50 litres respectively (Water UK)

Part of a bigger commitment

Rescuing surplus produce sits alongside the rest of our sustainability work. We grow our own herbs to cut food miles, we turn leftover croissants into caramelised flat croissants, and we were shortlisted for the Sustainability Award for Caterers 2025. Corporate clients increasingly ask about the environmental footprint of their events. Independent reporting like this means we can answer with real figures, not vague promises.

Planning a meeting, conference or reception in Central London and want the catering to match your sustainability goals? Get in touch with the Mayfair Catering team. We cater at Cavendish Venues across the City and West End. For smaller office occasions, our sister brand City Canapé Company offers sustainable canapé delivery in London.