Achieving consistent dough production
In this mini-series, we take a look at the key production challenges bakeries face. First up, achieving consistent dough production.
Why is it important?
The UK’s leading bakeries aim to produce a repeatable, high quality loaf, as efficiently as possible. At the beginning of the baking process flour is mixed with water and other ingredients to make dough. It follows that inconsistent dough production will inevitably lead to poor loaf quality downstream in the form of varying colour and texture. See the diagram below for a typical bread manufacturing process:
For bakers, being able to produce a consistent dough is integral to repeatedly manufacture the high quality loaves that their customers demand. Without consistent dough it also becomes almost impossible to optimise the remainder of the baking line process for quality, cost-effectiveness and consistency because of variances in the dough.
What are we aiming for?
Bakeries are aiming to minimise the variance of their dough in terms of ingredient ratios, consistency and mix energy. By minimising the variance of the dough, manufacturers can optimise the rest of the baking process to consistently produce a high quality loaf. This is challenging and manufacturers and invariably bakeries are reduced to applying on-line changes to ingredients to try and maintain some stability.
For instance, during the mixing phase, maintaining consistent temperature of the dough is imperative. If the temperature isn't right, the fermentation rate will be faster or slower during the proofing period, which will influence the volume of the bread and the colour of the crust.
What can we do about it?
It’s important to stress here that consistent dough is a complex challenge because of the wide range of factors that can lead to variances. OAL has undertaken a significant amount of root cause analyses of dough production to minimise these variances, including working with GE to build models that identify causality of such variances.
We have found the key drivers for consistency are accuracy and repeatability of ingredients feeds, temperatures, and understanding the role that moisture plays in the process. For instance, moisture content in the batched flour is largely influenced by the delivery air temperature and pressure. Hence the ability of a system to maintain the same temperature and pressure will have a direct effect on the varying moisture content of the dough produced.
OAL has helped bakeries and production plants identify and rectify the root causes of inaccuracies within their operations by analysing and stabilising these controlling variances. A major change has been to switch to vacuum transfer systems for ingredients.
Vacuum transfer of ingredients
OAL Group is a strong advocate of transferring ingredients under vacuum as opposed to blowing. The key benefit of vacuum transfer is the huge reduction in the amount of energy added during flour transfers. This directly results in steady, predictable development of the dough temperatures and more even proofing, in turn improving the consistency of crust colour and volume control.
Since 2010, OAL has been one of the most active suppliers of dry materials handling systems in the UK bakery industry. Over this period, we have commissioned over £30 million worth of new dry materials handling systems.