Energy use in bread baking

Abstract

A study was made of the energy used in production of standard, white, sliced bread in three UK bakeries. The production chain studied covered all stages from receipt of flour at the bakery to arrival of bread at the retail outlet: primary energy use from all sources averaged 6.99 MJ kg‐1 bread. In the complete production system for standard bread, including wheat growing, flour milling, baking and retailing, primary energy consumption was 14.8 MJ kg‐1 bread and the energy subsidy (primary energy input: food energy output) for the system was 1.49. Primary energy used in home baking was dependent on the degree of loading of the oven and varied from 4.24–16.05 MJ kg‐1 bread baked in a gas oven and from 10.84–54.76 MJ kg‐1 bread baked in an electric oven. In comparison with mashed potato, roast beef and reheated canned corn, standard bread showed the lowest energy subsidy by a factor of at least five. The energy subsidy for standard bread production was only one‐seventh of the figure which applies to the food system as a whole. The findings suggest that bread is the most energy efficient staple food product of an industrialised food production system.