Study finds pea gin could be just the tonic for world's rainforests

Would you drink gin made from peas?

Study finds pea gin could be just the tonic for world's rainforests

Research involving a Trinity College botanist and a lecturer at NUI Galway may have found a new way of producing gin that could do its bit to save the world’s rainforests.

What they discovered may also lead to a new method for producing other alcoholic drinks and for creating greener biofuels.

Gin production – which includes cultivating wheat as well as the production of enzymes, heat, electricity, packaging materials and transport – give rise to greenhouse gas (GHG) emissions of 2.3 kg CO2 equivalent (eq.) per 70 cl bottle of gin, or 160 g CO2 eq. per large measure (50 ml).

According to lead author of the study, Theophile Lienhardt, every large measure of gin is like driving your car for a kilometre.

He said: "In terms of climate change impact, sipping a large measure of gin is similar to consuming a small serving (150 ml) of milk, or to driving one km in a petrol car."

His international team of researchers included Professor Mike Williams, a botanist from Trinity College Dublin’s School of Natural Sciences, and they teamed up with a distillery manager to find out the environmental footprint of the aperitif.

To see if there were environmentally better ways to produce the drink, experts at Arbikie Distillery in Scotland ran trials in which the kernels of dried, de-hulled peas are milled and fermented in place of mashed wheat grain.

Professor Williams said: “Peas – working with specialised bacteria in their roots – are able to convert nitrogen from the atmosphere into biological fertiliser.

"As a result, they don’t require applications of polluting synthetic nitrogen fertilisers, which are widely and heavily used in industrial agriculture."

Co-products from one litre of pea gin substitute up to 0.66 kg of soybean animal feed, which is twice as much as can be gained from the production of wheat gin. In fact, when the potential avoidance of GHG emissions from substituted soybean cultivation, deforestation, processing and transport are also taken into account, the environmental footprint saving can exceed the GHG emissions arising from production – effectively making pea gin carbon neutral.

Prof. Williams said: "Pea hulls and distillery co-products provide protein-rich animal feeds that can replace soybean imported from Latin America, where cultivation is driving deforestation.”

Dr Pietro Iannetta, a molecular ecologist at the James Hutton Institute who led the study, said: “We found that the environmental footprint of pea gin was significantly lower than for wheat gin across 12 of 14 environmental impacts evaluated, from climate change, through water and air pollution, to fossil energy consumption.”

Also, if we were to make another adjustment to our gastronomic decision-making, we could do even more for the planet.

Lecturer in life cycle assessment at Bangor University and NUI Galway, Dr David Styles, added: “Of course, if we wanted to more dramatically shrink our environmental footprint and reduce deforestation, we could eat those peas directly to provide our protein and fibre requirements – instead of drinking gin and eating beef fed on the co-products.”

The study, which was part of the pan-European project TRansition paths to sUstainable legume-based systems in Europe: TRUE, was recently published in the scientific journal Environment International.

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