Problems and Solutions
There are often problems to which bakers large and small and their suppliers need an answer.
From time to time we shall feature a frequently found problem and its solution. In most cases we shall give a scientific and practical explanation of the problem.
Further examples can be found in the book ‘Baking Problems Solved’ - ISBN 1 85573 564 4 Publisher: Woodhead Publishing Ltd.
Archived Solutions:
- Wrinkled or collapsed fruit buns
- Large indentation at base of loaf
- Fruit cake dry eating and crumbly after a few days storage
- Soggy pastry with apple pies
- Collapse of doughnuts and excess of fat absorption
- Sticky icing on éclairs
- Crust shelling on frozen products
- Black dots on the crusts of cakes
If you require a copy of any of our archived solutions, please contact us at info@baketran.com
Shrinkage with pastry and biscuit products
Description:
| We make a number of different short and laminated pastry products and plain (low fat, low sugar) biscuits and are noticing that we get variations in product shape. It appears that the products are shrinking during baking. The extent and nature of the shrinkage seems to vary between products. We are using a manual brake for our pastry products and a simple sheet-and-cut plant for our biscuits. We are particularly concerned with our croissant and we would prefer to make them with the ends joined to give a ring shape.in the crumb. |  |
Explanation:
Controlling shrinkage with sheeted products is not easy because there are so many different ingredient, recipe and process factors which have an impact. The nature of the shrinkage tends to be products specific; sometimes there are simple solutions but in many cases they are complex.
First, it is useful to understand why shrinkage occurs. The shrinkage is most commonly related to the level of gluten development in the paste or dough. A primary aim in the manufacture of pastries and biscuits is to limit the development of gluten in the mixer through the choice of raw materials, recipe and mixing methods.
After the paste leaves the mixer, further work is done on the paste and dough when it is sheeted. In addition to increasing the level of gluten development in the dough, the sheeting process is most often carried out in the same direction as the material passes down the plant. This ‘uni-directional’ sheeting action tends to build up tension in the dough sheet in one direction. Gluten is visco-elastic and when the paste is cut from the sheet the tension is released and so the sheet tends to shrink back.
The degree to which pieces shrink and the exact change in shape depend on the nature of the product; for example square products tend to become rectangular and round ones elliptical. With croissant there is a further change in shape when the two ends are bent to form a ring and if the paste is particularly elastic there will be a tendency for the piece to try and return to the shape that it was when it was curled (i.e. straight).
Solution:
The materials – you may want to choose a flour with a lower protein content to limit gluten formation or add a small proportion of heat-treated flour in which the proteins have been denatured.
Recipe – the problems are greater with lower recipe fat levels. This can be a particular problem with the trend to reduce fat levels in bakery products to deliver a healthier product.
Mixing – you may want to investigate changing to a multi-stage mixing method; for example, based on creaming the fat and flour to try and limit gluten formation. Avoid excessively long mixing times.
Re-work – you may find it better to add re-work to the mixer rather than sending it back to the sheeting head. The use of re-work should be strictly controlled in terms of its level of addition, temperature and age because changes in re-work pH are known to be contributor to product shrinkage.
Resting periods – it is common practice to allow short periods of rest during processing to allow the paste to ‘relax’.
Cross-pinner – for many products and your croissant in particular you will need to use a ‘cross-pinner’. This is a small roller which travels at right-angles to the paste sheet during processing and evens out the tensions in it. The samples of croissant shown in the photograph were corrected in this manner.
Additional information:
Further information is given in our publications:
• Baked Products: Science, Technology and Practice.
• Bakery Food Manufacture and Quality: Water Control and Effects, 2nd edition
If you have a problem that has puzzled you for a long time, then please email us details with a photograph to info@baketran.com
