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Reducing carbon emissions – the Maltsters view

For good business reasons, maltsters are managing their operations with regard to climate change and particularly with respect to the welter of legislation and environmental pressures associated with it. However, there is also enlightened self-interest in the short-term, as many actions taken to address climate change issues also help to minimise waste in the maltsters’ supply chain, to the benefit of all in that chain from growers to consumers.

The first impact of climate change is the need, driven by corporate and social responsibility of maltsters and their customers, to reduce the carbon footprint of malt. The MAGB developed a carbon footprint calculator some years ago which has been used by UK maltsters as a single platform in order to avoid spurious comparisons between different methods of calculating greenhouse gas (GHG) emissions.

The immediate lesson of this calculator was that embedded carbon in the barley delivered to a maltings contributed over 60% of the carbon footprint of the finished malt. Added to the primary fuel and electricity consumed within the malting process, around 95% of the malt footprint could be accounted for. Such simplicity gave hope of focus to efforts to reduce the footprint: however, the energy requirements of malting have been subject to improvement for the whole twentieth century and before, so further gains will be hard won.

As for the GHG emissions associated with growing barley, the majority come from nitrogen fertiliser manufacture and use – and here the maltsters found themselves to be pushing at an open door. Fertiliser manufacturers were already looking to reduce nitrous oxide emissions during their operations, and the footprint of their product has been reduced substantially over the past few years for most producers. In the longer term, energy consumption of fertiliser production could be forecast to fall as the Haber Bosch process is further refined.

Use of organic wastes, converted to compost and anaerobic digestate (AD), could replace industrial nitrogen fertilisers to a great benefit in reduced carbon footprint, but these materials are not readily accepted for use on growing barley by some malt users. Pilot use by maltsters and individual customers is one way ahead; another is the possible agreement on a white list of materials to be used in compost and AD production.