The water footprint of soy milk and soy burger and equivalent animal products

As all human water use is ultimately linked to final consumption, it is interesting to know the specific water consumption and pollution behind various consumer goods, particularly for goods that are water-intensive, such as foodstuffs. This information is relevant, not only for consumers, but also for food producers and processors, retailers, traders and other businesses that play a role in supplying those goods to the consumers. The objective of this study is to quantify the water footprints of soy milk and soy burger and compare them with the water footprints of equivalent animal products (cow’s milk and beef burger). The study focuses on the assessment of the water footprint of soy milk produced in a specific factory in Belgium and soy burger produced in another factory in the Netherlands. The ingredients and sources of these ingredients are taken according to real case studies. We analysed organic and non-organic soybean farms in three different countries from where the soybeans are imported (Canada, China, and France). Organic production, which relies on animal manure, compost, biological pest control, and mechanical cultivation to maintain soil productivity and control pests, excluding or strictly limiting the use of synthetic fertilizers and pesticides, reduces soil evaporation and diminishes the grey water footprint, ultimately reducing the total water footprint. The water footprint of 1 litre soy milk produced in Belgium amounts to 297 litres, of which 99.7% refers to the supply chain. The water footprint of a 150 g soy burger produced in the Netherlands is 158 litres, of which 99.9% refers to the supply chain. Although most companies focus on just their own operational performance, this study shows that it is important to consider the complete supply chain. The major part of the total water footprint stems from ingredients that are based on agricultural products. In the case of soy milk, 62% of the total water footprint is due to the soybean content in the product; in the case of soy burger, this is 74%. Thus, a detailed assessment of soybean cultivation is essential to understand the claim that each product makes on freshwater resources. This study shows that shifting from non-organic to organic farming can reduce the grey water footprint related to soybean cultivation by 98%. Cow’s milk and beef burger have much larger water footprints than their soy equivalents. The global average water footprint of a 150 gram beef burger is 2350 litres and the water footprint of 1 litre of cow’s milk is 1050 litres. These figures include the water footprint of packaging, but this component contributes no more than a few per cent to the total.