Previously, frozen raw dough could not match the quality of fresh made. But now, one of the latest developments in freezing technology has changed this opening great possibilities for in-house bake-off stores.
The smell and aroma of freshly baked bread should not be underestimated in terms of its effects on consumers. The aroma and atmosphere around a counter with freshly baked bread has been proven to increase sales. That is why in-house bake-off stores are rapidly becoming more popular in Asia.
In the past, the in-house bake-off store needed to start from fresh raw dough in order to produce fresh bread in the store. This was because frozen raw dough did not measure up to the quality of fresh raw dough made in store, the most obvious shortcoming being variations in size due to poor freezing. Today, however, the latest technology makes it possible to freeze raw dough without compromising quality.
An in-depth look at the structure of dough reveals why freezing of raw dough is so different from other applications.
Dough consists of four basic ingredients: wheat flour, water, yeast and salt. Wheat flour in turn contains unique proteins which, when hydrated with water, form a protein structure called gluten. When mixed and further processed, gluten becomes elastic and incorporates bubbles that hold the carbon dioxide produced during fermentation. Yeast is needed to aerate the dough through the production of carbon dioxide gas during fermentation. The gas is then kept within the gluten network, which gives the bread its volume.
Freezing of dough requires precise control of the process parameters that can affect the properties of the gluten network and yeast activity. To maintain its functionality, gluten requires fast freezing, during which the ice crystals formed will be small. Slow freezing causes the formation of large ice crystals that destroy the continuous gluten network and hence leads to poorer quality. To reduce this and lengthen the shelf life the use of a high-quality flour, with a high level of gluten protein, is usually recommended when making dough for freezing. When producing frozen dough for longer storage times, an increased amount of yeast is also recommended.
Freezing too fast, or having too low a temperature of the freezing medium, poses its own problems. Briefly put, although fast freezing is good for the gluten structure, it is likely to adversely affect yeast survival. Slow freezing is not good for the gluten structure but is good for yeast survival.
In industrial-scale production of frozen dough, uniformity is another important factor.
Variations in the speed of freezing will cause variations in the amount of surviving yeast for dough products, resulting in products of different sizes when they are subsequently baked. This dilemma highlights the importance of tight control of airflows, temperature and air distribution in an industrial freezer.
Spiral freezers that incorporate a self-stacking belt, widely used in Europe for bakery products, meet these requirements.
This type of belt features side links with strategically placed holes, making it possible to direct the airflow evenly, giving the controlled freezing that dough products require for good, uniform bake-off results. The efficient airflow of self-stacking freezers also minimises product weight loss.
To meet the processors' requirements for the best quality baked products, the freezing process must be adaptable to different types of dough and must ensure uniform airflow and even temperature for each product. Spiral freezers with self-stacking belts offer this adaptability and has been a well-proven concept for different bakery products such as croissants.
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