The popular breakfast pastry is unique in its light flaky texture and buttery flavour. How are croissants obtained? Their production requires mixing, kneading, laminating, cutting, forming, proofing, baking, cooling, and packaging; for consistent, automated manufacturing, this means dedicated croissant lines.
Technology solution experts from Rademaker, RONDO and Fritsch have shared with European Baker & Biscuit a guide through each module, component and feature making up a croissant line, as well as typical configurations to look for.
Croissants start off as butter (or margarine), yeast, sugar, water, a touch of salt, and flour. Before they achieve their shape – classic crescent or variants, these ingredients must first make a laminated dough sheet. To manufacture this, Rademaker developed the Sigma Laminator: “A typical Sigma Laminator starts with a (pre-) sheeter. Rademaker developed a variety of (pre-) sheeters, all based on specific types of dough. The choice for the required (pre-) sheeter is recommended by Rademaker experts, and it is based on the dough type and the required characteristics of the product,” experts from the Dutch company told us.
After the dough sheet has been created, fat is applied on top of the dough sheet, with the help of a pump. “Rademaker’s fat pump is unique in the market, having a very high dosing accuracy and fat-friendly processing method,” explain the specialists. The laminating process then continues with folding the fat into the dough sheet. “Based on the type of the fat used, the dough sheet can optionally be led through a cooling/resting tunnel. Subsequently, after several high accuracy laminating sequences and the optional cooling/resting tunnel, the laminator section delivers a high-quality dough sheet, heading towards the croissant make-up section,” they added.
The heart of the Rademaker croissant system is the cutting and turning unit, which produces the dough triangles at the required size and weight. The system starts with the process of cutting the dough sheet into several dough lanes. This process step defines the size of the triangles. The dough lanes are separated by the spreading conveyor, to create the working space and to align the dough lanes for the cutting unit, which is the next process step. The cutting unit cuts the required dough triangles and defines the base dimension, after which the turning unit turns the triangles at the right orientation and position. The dough triangles are then aligned by the aligning unit. The last step in this process is moistening the dough triangles with water. Moisture enables the dough triangle to stick during the molding process, that follows the cutting and turning processes.
Rondo: a standard industrial solution
In general, an industrial croissant line consists of the following three main elements: dough band former, lamination line and croissant machine, Alexander Weissbach, head of technology and product management, RONDO, told us. The main process steps of manufacturing croissants with lines by the Swiss expert are: “dough band forming, applying of lamination fat (margarine or butter), creation of the dough/fat layers, creation of a dough band with defined width and thickness (all these steps take place on the lamination line), length cutting of the dough band into stripes, cutting of dough triangles, turning of the dough triangles, applying of fillings where applicable, curling of the triangle to croissants (all these, on the croissant machine). Subsequently panning and bending of the croissants can be processed on RONDO equipment,” Weissbach explained.
While there is no single, typical configuration for industrial laminating lines, RONDO designs and produces industrial croissant lines tailor-made according to manufacturer requirements. “RONDO ASTec croissant lines can process up to 8 tons/h,” he illustrated. “Specific customer requirements influence the line’s layout, but other aspects have also a big influence. Industrial croissant lines differ from one regional market to another and are very much influenced by the type of croissant produced. Pre-fermented frozen croissant (typically processed with butter) or long shelf-life croissant (typically processed with margarine) require a different layout of the lamination line,” he added.
RONDO offers several types of dough band formers for feeding industrial ASTec croissant lines. “For long shelf-life croissants and for frozen croissants with a long storage time, we recommend the dough band former MIDOS. This dough band former does not damage the gluten network because it is designed for low stress processing,” explained the specialist.
Compact solutions are normally fed batch-wise with dough blocks. “Dough blocks are either produced with dough sheeters, e.g. Rondostar, or on compact lamination lines, e.g. RONDO MLC. Dough blocks are normally rested for several hours and then processed on an automatic croissant machine, e.g. Cromaster. The capacity of these compact solutions is between 5,000 and 25,000 croissants per hour,” according to the company’s representative.
Compact solutions are characterized by high flexibility and fast product change-overs. To realize a low footprint, these installations are not equipped with a U-laminating line with two folding stations or even with resting belts. Additionally, compact solutions can often be multi-functional lines. “Customers can produce croissants and also bread and pastries on these automated lines. They make it easy for the customer to react to changes of the market or seasonal variations.”
For industrial production, the German specialist’s solutions have outputs of up to 135,000 pieces per hour and allow significant weight variations, for products of up to 150g. The IMPRESSA croissant line is not only produces croissants in every shape, but also the entire range of coiled products fully automatically. The line cuts and turns the triangular dough pieces in a single fluent step, for consistent shapes, accurate weight and positioning required by continuous high-speed processing.
“Reproducible quality in dough weight, flexible number of layers, symmetrical shape, very high capacity, accurate placing on trays, short downtime for product changeover” are challenges specific to croissant production, said Claus Hetzner, product management, Fritsch. To tackle these and other customer requirements, customizations the company proposes include “flexible lamination and layering systems (L3000), high-precision cutting and turning (CCT), efficient long rolling and precise filling at high speed, and a reliable coiling system (CSVSA)”.
Module and process synchronisation
RONDO synchronizes process steps by using the latest technology like brushless motors, ethernet connections and a fast and modern SPS system. “RONDOnet, the state-of-the-art control system offers the entry in Industry 4.0. Easy and safe to work with, this control system supports the customer by providing management data and maintenance support.
Rademaker shares insights into its solutions: “Our production lines are equipped with a unique cascading system. This system synchronizes the different module speeds to optimize the dough processing. In addition, the feeding towards the production line is done by a (pre-)sheeter. Rademaker has several (pre-)sheeters available. The choice for the right solution depends on the type of dough and the required end product.”
You can read more in our print magazine European Baker & Biscuits (Nov/Dec 2017)!