Life cycle assessment of bread production - a comparison of eight different scenarios

Posted by adrian
Publication year: 
Food, Plants
Bread (conventional & organic)
Quality and sources
Is the study a: 
Detailed LCA
Jörg Braschkat
Andreas Patyk
Markus Quirin
Guido Reinhardt
Practitioner(s) type: 
Functional unit: 
1 kg bread ready for consumption at home
Goal and scope of the summary: 
Goal: Which way is the most environmentally friendly way of bread production? Which crop production method (conventional, organic), which milling technology (industrial or domestic mill) and which baking technology (large bread factory, bakery, domestic bread maker) is the most advantageous one from the ecological point of view? Which one of the process steps, including the transports, does account for the highest or lowest environmental effects? Where, within the whole bread production chain, is it feasible to introduce ecological optimisations or to reduce environmental effects, and what are the corresponding recommendations? Scope: Production in Germany The life cycles assessed in this comparison start off with the crop production, incorporating all steps of the conventional as well as organic wheat production, from soil cultivation up to harvest. Within flour production it is assumed that the grain is ground either in an industrial mill or in a domestic mill. Regarding bread production three different options were considered: a large bread factory, a bakery and a private household using a bread maker. Standard transports with 23 t trucks (distance 100 km, outward bound fully loaded, return empty) were assumed for the following routes: transports of grain from the farm to the mill or retailer, transports of flour from the mill to the bread factory or bakery or retailer and transports of bread from the bread factory to the retailer. For the transport of grain, flour and bread by the end-consumer it was initially assumed, that the transports were done either on foot or using a bicycle and thus, the energy demand and emissions were either zero or not significant. Finally, additional scenarios for the transport of the bread by the consumer using a car were calculated.

Organically produced grain has to be preferred to grain
that was produced conventionally regarding all impact
categories except land use.

The baking
process was the most energy-consuming step of the entire bread production process accounting
on average for 64% of the total energy demand. The baking process using a domestic
bread maker requires 3 times more energy than in a factory and in the bakery, energy demand
is still twice as high than in a large bread factory. Due to the close correlation between energy
demand and greenhouse effect the same applies to the greenhouse effect as well. Besides, using
a conventional oven for baking bread at home requires more energy on average than a
bread maker and therefore this option was not considered in this study. 

Crop production, however, is much more important regarding the greenhouse effect because
of the amount of N2O released and for that reason the assessment not only depends on the
baking process but also on the way, how the crop was produced. Regarding ozone depletion,
acidification and eutrophication the situation is completely different. In these cases, all of the
scenarios based on organic crop production are most beneficial, whereas the remaining downstream
processes did not entail any further differentiation of the results 

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